环烷

For the synthesis of NHC precursors, there are also several routes: condensation of glyoxal, amines and paraformaldehyde; alkylation of imidazole or monosubstituted imidazole with alkyl halide; annulation of ortho esters and 1,2-diamines; ring closure of hydrazines or amides with acetic anhydride; reduction of thiones with Na/K in THF.

关于N-杂环卡宾前体的合成途径主要有：乙二醛、伯胺和多聚甲醛的缩合反应；卤代烷与咪唑及其取代咪唑的烷基化反应；原甲酸酯与1，2-二胺的成环反应；肼或酰胺与酸酐的环化反应；用Na/K对环硫脲化合物的还原反应。

In this disseration, the cationic ring open-polymerization mechanism of THF、 butylene oxide and ethylene oxide were studied on the basis of electronic microstructures by using quantum chemicl method.

本文选取四氢呋喃、环氧丁烷和环氧乙烷的阳离子开环聚合为研究对象，运用量子化学方法从微观层次上对烷氧基化开环聚合过程进行了较为全面的研究。

In the condition of 1 MPa O_2 and 413 K for 4 h, the conversion of cyclohexane is 16.9%, and the total selectivity of cyclohexanol and cyclohexanone is 93%.

在该反应条件下，环己烷的转化率为16.9％，环己酮和环己醇的总选择性为93％。

CH3OH could attack the phosphor atom in 1,3,2-dioxaphopholane of compiound (1) to give O-methyl O-hydroxyethyl-O-phthalimidoethyl thiophosphate in 85% yield; in the presence of potassium hydroxide aryl selenol could attack the carbon atom in 1,3,2-diox-aphopholane of the cyclic phospholipid conjugate of N^1-(2-furanidyl)-N^3--5-fluorouracil to give the corresponding product of ring-opening in high yields.

在室温下，以异丙醇作溶剂，苯硒酚与化合物2不反应。在氢氧化钾存在下，以异丙醇／水作溶剂（体积比20：1，在室温下，硒酚可以有效地进攻中化合物2中1，3，2-二氧磷杂环戊烷中的碳原子生成相应的开环产物。按照这一反应条件，顺利实现了硒酚对N^1-（2-呋喃基）-N^3-羟烷基-5-氟脲嘧啶硫代环甘油磷脂缀合物的亲核开环，生成甘油骨架的端碳原子上带有芳硒基新颖的磷脂核苷缀合物。

The photocycloaddition of 1-naphthonitrile (1-NpCN) and 2,3-dimethyl-2-butene in cyclohexane or benzene gave cyclobutane 3 primarily,but that of 2-NpCN gave azetine 6 asthe major and cyclobutane 5 as the minor product in low conversion photolysis.

在低转化光解情况下，1-萘甲腈(1-NpCN)和2，3-二甲基丁烯-2在环已烷或苯中的光环加成反应主要得到环丁烷3，但2-NpCN主要得到氮杂环丁烯6和少量的环丁烷5，三氟醋酸量增加抑制1-NpCN和DMB的光环加成反应，表明TFA与基态及单激发态1-NpCN生成非光反应的复合物，它也淬灭(1-NpCN-DMB)激基复合物。

The photocycloaddn. of 1-naphthonitrile (1-NpCN) and 2,3-dimethyl-2-butene in cyclohexane or benzene gave cyclobutane I primarily, but that of 2-NpCN gave azetine II as the major and cyclobutane III as the minor product in low conversion photolysis. The photocycloaddn. of 1-NpCN with DMB is retarded by increasing amts. of trifluoroacetic acid which is shown to form non-photoreactive complexes with ground state as well as with singlet excited state 1-NpCN. It also quenches the *(1-NpCN-DMB) exciplex.

在低转光解情况下，1-萘甲腈(1-NpCN)和2，3-二甲基丁烯-2在环已烷或苯中的光环加成反应主要得到环丁烷3，但2-NpCN主要得到氨杂环丁烯6和少量的环丁烷5，三氟醋酸量增加抑制1-NpCN和DMB的光环加成反应，表明TFA与基态及单激发态1-NpCN生成非光反应的复合物，它也淬灭^*(1-NpCN-DMB)激基复合物。

The result was compared with oxidations of cyclohexene without irradiation and at irradiation without catalyst.

另外，本文还研究了各种类型的催化剂在中压汞灯下光催化环己烯的氧化反应，结果表明，无论上述的哪种催化剂，在中压汞灯下光催化环己烯氧化反应，都得不到环氧环己烷，生成的产物主要为水和二氧化碳。

The method ensures safety and enhances heat transfer, and can remarkably improve the oxidizing reaction speed of cyclohexane and the total selectivity of cyclohexanone, cyclohexanol and cyclohexyl hydrogen peroxide.

该方法具有安全性，强化了热量的传递，可显著地提高环己烷氧化反应速度，提高环己酮、环己醇和环己基过氧化氢的总选择性。

METHODS: Collaborative meta-analyses were undertaken of 194 unconfounded randomised trials of adjuvant chemotherapy or hormonal therapy that began by 1995. Many trials involved CMF (cyclophosphamide, methotrexate, fluorouracil), anthracycline-based combinations such as FAC (fluorouracil, doxorubicin, cyclophosphamide) or FEC (fluorouracil, epirubicin, cyclophosphamide), tamoxifen, or ovarian suppression: none involved taxanes, trastuzumab, raloxifene, or modern aromatase inhibitors.

对194个开始于1995年的关于辅助化疗或激素治疗的随机试验进行meta分析，许多试验包含了CMF(环磷酰胺、氨甲喋呤、氟尿嘧啶)，蒽环药物为基础的联合化疗比如FAC(氟尿嘧啶、阿霉素、环磷酰胺)或FEC（氟尿嘧啶、表阿霉素、环磷酰胺）及他莫昔芬或卵巢去势；无一包含紫杉烷类、赫赛汀、雷洛昔芬及芳香化酶抑制剂。

The reactions involved in the co-curing are: cyclodimerization and cyclotrimerization of cyanates, polyetherfication of epoxy groups and cyclotrimerization of cyclic dimers, as well as the formation of oxazolidinone rings.

反应历程首先是氰酸酯发生自聚反应形成二聚体或三聚体，然后二聚体可进一步共聚形成三嗪环，此过程伴随着环氧基的聚醚反应，最后是三嗪环与剩余的环氧基反应形成NFDA1唑烷酮。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失