Synthesis and Characterization of a Novel Azo Compound with 'Dumbbell Shape';
“哑铃状”偶氮化合物的合成与表征
The dumbbell-shape compounds, quaternary ammonium salts(3) of 4,4′-bipyridines bridged 2,2′-bipyridine in yields of about 90%, were synthesized by solid grinding at room temperature from quaternary ammonium salts(2) of N-substituted 4,4′-bipyridine which were prepared via the reaction of 4,4′-bipyridine and tosylate(or benzyl bromide) containing stopper in yields of 60%~90%.
采用室温固相研磨的方法,4,4′-联吡啶与连有阻塞基的乙氧乙醇磺酸酯(或苄溴)反应,得到单取代的4,4′-联吡啶六氟磷酸盐(2),2再与α,α′-二(溴甲基)-2,2′-联吡啶反应,得到哑铃型化合物——2,2′-联吡啶桥连的双-4,4′-联吡啶六氟磷酸盐(3),收率约90%。
Molecular shuttle locate foreland research field in organic chemistry, they are composed of one cyclic compound and a dumbbell-shaped compound.
哑铃型化合物作为构筑轮烷和分子梭的关键砌块,本文综述了现在所报道的含4,4’-联吡啶哑铃型化合物的类型和合成方法,4,4’-联吡啶的成盐反应一般是以无水乙腈为溶剂,加热回流数天,产率很低,同时有副产物产生,产物的分离、纯化困难。
This approach was used to simulate plane Couette flows of dilute polymeric fluids by the FENE dumbbell mode.
采用确定性方法数值求解了聚合物稀溶液的微观-宏观模型,其中,宏观尺度上用有限体积法求解守恒方程,介观尺度上用谱方法求解Fokker-Planck方程和聚合物对偏应力张量的贡献,模拟了聚合物稀溶液FENE哑铃模型的平板Couette流动,给出了速度随时间变化的剖面图,分析了移动平板速度、哑铃的量纲1有限拉伸参数和Deborah数对流动的影响,同时也验证了有限体积法与谱方法结合求解聚合物微观-宏观模型的有效性。
Dumbbell exercise and wall-scaling 6.15-6.30
哑铃体操及爬墙 6:15－6:30
The dumbbell is raised20 times by the sportsman everyday.
这个哑铃每天被运动员举起二十次。
The dumbbell has been raised by the sportsman20 times.
这个哑铃已经被运动员举过二十次。
The dumbbell was raised20 times by the sportsman yesterday.
昨天,这个哑铃被运动员举起二十次。
The dumbbell will be raised20 times by the sportsman tomorrow.
明天,这个哑铃将被运动员举起二十次。
Research on effect of Cheng-yu cities and the model of the periphery style unity;
成渝双城效应及“哑铃共同体”模式探析
Dumbbell Model of Business Competition in the Age of Intellectual Economy;
“哑铃”模式:知识经济时代企业竞争之道
Strength and Fatigue Life Analysis of Dumbbell Pin for Mining
矿用联接哑铃的强度与疲劳寿命分析
A Fast Synthesis and Analysis Method of Dumbbell-Shaped Defected Ground Structure
哑铃型DGS的快速分析和综合方法
Design and Simulation of Microstrip Antenna with EBG Structure of Etching Dumbbell Shape Structure
哑铃形EBG结构微带天线的设计与仿真
Discussion on Calculation Pattern of Concrete-Filled Steel Tube with Dumbbell-shaped Section
钢管混凝土哑铃型截面计算模式分析
Dumbbell Tenement: For Low-income City Residents During the Earlier Urbanization in America
美国城市化初期的贫民住宅——“哑铃公寓”
The dumbbells and barbells are of course effective and are able to take effect in a short time.
西方的哑铃、杠铃等固然有效，而且可以短期内见效。
The Effect of Alternate Exercising Dumbbell Flying Bird and Barbell Pushingand Lifting on the Development of Chest Muscles;
哑铃飞鸟与杠铃推举交替练习对发展胸肌的影响
Pipe should be bent out as the dumbbell shape if the width space for piping is shorter than mininum bending diameter.
布管幅宽小于最小直径时要作成哑铃形。
A heavy object, such as a dumbbell, lifted for exercise or in athletic competition.
投掷器械用于锻炼或体育竞赛的重物，如哑铃
Now please give me ten dumb-bells, three chest-expanders and six chronographs.
好，请给我拿10个哑铃，3个拉力器，6块跑表。
Study on the Synthesis of Dumbbell Molecule Shuttle Compounds by Method of Solvent-free;
无溶剂法合成分子梭哑铃型化合物研究