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needle
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     On Needle
     说“针”
短句来源
     7 needle.
     穿刺针为 14G和长 7号注射针。
短句来源
     The needle was MR-compatible (Daum, Germany).
     活检针采用德国Daum公司的磁共振兼容性活检针。
短句来源
     The disposable LP (Lumbar pancture) needle
     一次性使用的腰穿针
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  needle
The multi-walled carbon nanotubes (MWCNTs) should be assembled with a sharp metal needle of nano-scale radius, for which the FE mechanism is more or less clear.
      
Using the ArcView Geographic Information System (GIS) platform, a case study was carried out by selecting the population of Pinus massoniana from a needle-and broad-leaved mixed forest community in the Heishiding Nature Reserve, Guangdong Province.
      
The motion of an ensemble of charged droplets in a constant electric field and in a nonuniform field between a needle-like electrode and a plane has been calculated by the molecular dynamics method.
      
Unexpected Formation of an sp2-Carbon Needle from Dimethyl Ether Vapor Under Mild Conditions on Exposure to Radiation from a Low
      
Experimental investigation of the characteristics of unsteady-state breakaway zones arising in a supersonic flow at a needle wit
      
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4-Methyl-2,6-dichloropyrimidine was prepared by heating 4-methyl-uracil with phosphorous oxychloride in the presence of phosphorous pentachloride; and it boiled at 97° at 7 mm, at 102° at 10 mm, or at 113° at 13 mm. 4-Methyl-2,6- dichloropyrimidine reacted with sodium methoxide in anhydrous methyl alcohol, forming 4-methyl-2,6- dimethoxy-pyrimidine, which was isolated by ether extraction and pnrified by vacuum distillation. Pure 4-methyl-2,6-dimethoxy-pyrimidine boiled at 85-87° at 7 mm, or at 103° at 13 mm,...

4-Methyl-2,6-dichloropyrimidine was prepared by heating 4-methyl-uracil with phosphorous oxychloride in the presence of phosphorous pentachloride; and it boiled at 97° at 7 mm, at 102° at 10 mm, or at 113° at 13 mm. 4-Methyl-2,6- dichloropyrimidine reacted with sodium methoxide in anhydrous methyl alcohol, forming 4-methyl-2,6- dimethoxy-pyrimidine, which was isolated by ether extraction and pnrified by vacuum distillation. Pure 4-methyl-2,6-dimethoxy-pyrimidine boiled at 85-87° at 7 mm, or at 103° at 13 mm, and melted at 62-65°. It was recrystallized from petroleum ether, m.p. 65-66°. In the above reaction, there was isolated a white solid, suspending in the ethereal solution and being collected separately. This white solid, considered as a by-product, was dissolved in hot water and acidified with acetic acid, whereupon it separated in needles. After recrystallization from water, it melted at 201-202°. It was tentatively assigned to be 4-methyl-2-methoxy- uracil. Further, 2,6-dialkoxy-pyrimidines were prepared similarly as 4-methyl-2,6-dimethoxy- pyrimidine: 4-Methyl-2,6-dichloropyrimidine reacted with sodium ethylate in anhydrous ethyl alcohol, forming 4-methyl-2,6-diethoxy-pyrimidine, which boiled at 110°/11 ram. 4-Methyl- 2,6-dichloropyrimidine was treated with sodium n-propoxide in normal propyl alcohol, forming 4-methyl-2,6-di-n-propoxy-pyrimidine, which boiled at 120°/5 mm. 4-Methyl- 2,6-dichloropyrimidine reacted with sodium iso-propoxide in isopropyl alcohol, forming 4-methyl-2,6-di-isopropoxy-pyrimidine, which boiled at 103°/3 mm. The action of sodium n-butoxide in normal butyl alcohoI upon 4-methyl-2,6-dichloropyrimidnie gave 4-methyl- 2,6-di-n-butoxy-pyrimidine, which boiled at 147-148°/5 mm. The action of sodium isobutoxide in isobutyl alcohol upon 4-methyl-2,6-dichloropyrimidine gave 4-methyl-2,6- isobutoxy-pyrimidine, which boiled at 132-133°/6 mm. The action of sodium isopentoxide in isopentyl alcohol upon 4-methyl-2,6-dichloropyrimidine gave 4 methyl-2,6-di-isopentoxy- pyrimidine, which boiled at 145-146°/3 mm. 4-Methyl-2,6-dichloropyrimidine reacted with sodium benzoxide in benzyl alcohol, giving 4-methyl-2,6-dibenzoxy-pyrimidine, which boiled at 231°/6 mm. 4-Methyl-2,6-dimethoxy-pyrimidine was heated in a sealed tube at 330-350°, giving the completely rearranged isomeric compound, 1,3,4-trimethyl-uracil, which was purified by vacuum sublimation at 130° at 10 mm and then by recrystallization from 95% alcohol. The latter melted at 107-109°. Nevertheless, 4-methyl-2,6-dimethoxy-pyrimidine was dis- solved in methyl iodide, and kept at room temperature in the dark with occasional shaking; whereupon the partially rearranged product, 2-oxy-3,4-dimethyl-6-methoxy-pyrimidine, gradually separated out. After recrystallization from absolutealcohol, it melted at 134-135.5°. Its structure was established as follows: Pure 2-oxy-3,4-dimethyl-6-methoxy-pyrimidine was heated with dilute hydrochloric acid for one hour; whereupon 3,4-dimethyl-uracil, m.p. 220-221°, separated out. This partially rearranged product, 2-oxy-3,4-dimethyl-6-methoxy- pyrimidine was heated at 335-350° and was again transformed into its stable and completely rearranged modification, 1,3,4-trimethyl-uracil, which was purified by vacuum sublimation and then recrystallization from 95% alcohol. The latter melted at 109-110°.

(1)4-甲基-2,6-二氯代嘧啶與鈉醇和醇的溶液作用,可以形成相應的2,6-二烴氧基嘧啶。 (2)4-甲基-2,6-二甲氧基嘧啶加熱至高温度即可轉變成其穩定結構的異構體1,3,4-三甲基-2,6-二羥基嘧啶。另一方面,在碘代甲烷催化劑的影響下,部份轉變成2-氧代-3,4-二甲基-6-甲氧基嘧啶;此化合物加熱卽可發生完全的轉變作用而形成其異構體1,3,4-三甲基-2,6-二羥基嘧啶。

From the Chinese drug, Chin-kuo-lan, there have been isolated a new crystalline alkaloid and a neutral principle. The new alkaloid, which is provisionally named calystigine, crystallized from a mixture of acetone and ether in brownish prisms, with a m.p. of 203°. It has a molecular formula of C_(25)H_(23)O_6N, according to analyses of its crystalline salts, which are (1) picrate, C_(25)H_(23)O_6N·C_6H_3N_3O_7, brownish needles, m.p. 220°; (2) nitrate, C_(25)H_(23)O_6N·HNO_3, yellow needles, m.p....

From the Chinese drug, Chin-kuo-lan, there have been isolated a new crystalline alkaloid and a neutral principle. The new alkaloid, which is provisionally named calystigine, crystallized from a mixture of acetone and ether in brownish prisms, with a m.p. of 203°. It has a molecular formula of C_(25)H_(23)O_6N, according to analyses of its crystalline salts, which are (1) picrate, C_(25)H_(23)O_6N·C_6H_3N_3O_7, brownish needles, m.p. 220°; (2) nitrate, C_(25)H_(23)O_6N·HNO_3, yellow needles, m.p. 233-234°; (3)hydrochloride, prisms, m.p. 230°; (4) hydrobromide, yellow needles, m.p. 232°; (5) perchlorate, C_(25)H_(23)O_6N·HClO_4, yellow needles, m.p. 268°; (6) methyliodide, C_(25)H_(23)O_6N·CH_3I, bright reddish needles, m.p. 238°. The neutral principle crystallized from a mixture of chloroform and ethanol in fine soft needles, having a molecular formula of C_(14)H_(16)O_4, m.p. of 191°, and a specific rotation of +32° in chloroform. It does not contain methoxyt and carbonyl groups, but reacts with bromine in acetic-acid solution to form a monobromide C_(14)H_(15)O_4Br, m.p. 214°.

從中藥金果欖(Calystigia hydraceae)中分得新植物鹼及中性物質各一種。新植物鹼暫時命名為金果欖鹼(calystigine),其分子式為C_(25)H_(23)O_(6)N,熔點202-203°,含量0.07%。此新植物鹼是一種叔胺鹼,極易與碘甲烷生成黄色結形的甲基季銨鹽,熔點238°。現已製得下列各種結晶鹽質:硝酸鹽,熔點233-234°;鹽酸鹽,熔點230°;氫溴酸鹽,熔點232°;高氯酸鹽,熔點268°;苦味酸鹽,熔點202°。 從金果欖中分得的中性物質,為白色針狀晶體,其分子式為C_(14)H_(16)O_4,熔點191°,[α]_D~(15)=+32°。產量約為0.92%。此中性物質對於醋酸酐和苯肼均無反應,但與溴液在醋酸中反應稜,生成一溴化物,C_(14)H_(15)O_(4)Br,熔點214°。

Two kinds of the Chinese drug, Pai-pu, obtained from the local market were subjected to an experiment. One of them has been identified to be Stemona sessilifolia, and the other not ascertained yet. However, a known alkaloid, tuberostemonine, has been isolated from the latter, which, therefore, is likely to belong to Stemona tuberosa. It has been found that the base of this alkaloid can be easily seperated from the mixture in the form of a crystalline hydriodide with a melting point of 252°, and further comfirmed...

Two kinds of the Chinese drug, Pai-pu, obtained from the local market were subjected to an experiment. One of them has been identified to be Stemona sessilifolia, and the other not ascertained yet. However, a known alkaloid, tuberostemonine, has been isolated from the latter, which, therefore, is likely to belong to Stemona tuberosa. It has been found that the base of this alkaloid can be easily seperated from the mixture in the form of a crystalline hydriodide with a melting point of 252°, and further comfirmed by analyses of its crystalline salts: perchlorate, m.p. 242° and methiodide, m.p. 236°. From the Stemona sessilifolia, a new alkaloid, provisionally named as sessilistemonine, has been isolated with an empirical formula of. C_(25)H_(35)O_7N, m.p. 172°, [α]_D~9=+122.5° (CH_3OH, 1%). It may form the following crystalline salts: (1) picrate, C_(25)H_(35)O_7N· C_6H_3O_7N_3, yellow needles, m.p. 165°; (2) perchlorate, C_(25)H_(35)O_7N·HClO_4, needles, m.p. 201-205°; (3) methiodide, C_(25)H_(35)O_7N·CH_3I, needles, m.p. 231-232°; (4) percrolonate, C_(25)H_(35)O_7N·C_(10)H_8O_5N_4, yellow needles, m.p. 236°.

從上海市購得的百部根中,分離出對葉百部鹼。其氫碘酸鹽的熔點爲252°。又從母液中分得一種氫碘酸鹽,熔點218°。 從直立百部中分得一新植物鹼,暫命名為直立百部鹼,C_(25)H_(35)O_(7)N,熔點172°, [α]_D~9=+122.5°。此植物鹼是一個叔胺鹼,並製得幾種晶體鹽。

 
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