查询词典 ring-pull can

Since aromatic ring is a very stable compound, it would needs very high activation energy to begin the ring opening reaction. It is therefore interesting to investigate how the micro-organism can catalyze this reaction in room temperature at natural buffer condition.

由於芳香环是一种非常稳定的化学结构，如果想要进行开环反应必要要经过极大的活化能，而了解生物体中是如何在常温的环境下进行这样的反应将会是非常有趣的题材。

To measure your ring size, you can use our Free Ring Sizer .

衡量你的戒指的大小，您可以使用我们的免费环赛泽。

This paper introduces the reason that the damper bars of the squirrel-cage rotor is easy to break, compares and analyzes the cases of fitting the fans on the end ring s and fitting the fans on the other site, The result shows that the number of broken bars can be reduced by fitting the fans on the clamp ring.

本文指出了转子断条现象，研究了断条原因，对端环上挂风扇与不挂风扇的情况进行了分析比较，并指出采用风扇挂在压圈上的结构，可减少断条事故的发生。

Chapter 1: The reactions of methylenecyclopropanes with phenylsulfenyl chloride or phenylselenyl chloride give cyclobutene derivatives along with ring-opened products in good total yields at 0 °C in various solvents. The reactions of methylenecyclopropanes with diphenyl diselenide give the di-phenylselenyl substituted ring-opening products which can be transformed to 2,5-dihydrofuran derivatives under the oxidation with hydrogen peroxide at room temperature.

在第一章中，我们发现亚甲基环丙烷类化合物在0℃时即可很快与苯硫氯或苯硒氯发生反应生成取代环丁烯类化合物和正常的开环产物；而与二苯基二硒的反应则需加热到150℃以上才能进行反应，生成的二苯硒基开环产物在双氧水氧化下可以转化为取代二氢呋喃类化合物。

A photonic crystal-air interface or line defect is utilized as a holophote or a partial reflective mirror to design a paralleled plane cavity, a single ring cavity structure and a multi-ring cavity structure. The method has simple design idea, good integration and wide application; by adopting the method, the self aligning photonic crystal lasers with different wave bands can be designed according to the luminescent characteristics of different materials; particularly, the utilization of semiconductor materials to design a light source of optical communication wave bands has more important practical value.

利用光子晶体-空气界面或线缺陷作为全反射或部分反射镜设计平行平面腔、单环形和多环形腔结构；该方法设计思路简单，集成性好，适用范围广，可根据不同材料的发光特性设计不同波段的自准直光子晶体激光器，特别是用半导体材料设计光通讯波段的光源器件具有更重要的实用价值。

Poly(ethylene-2,6,-naphthalate) is a newly developed polyester. The chemical structure of PEN can be described by replacing the benzene ring in poly with the stiffer naphthalene ring.

聚萘二甲酸乙二酯是一种近年来获得较大发展的高性能聚酯材料，其分子结构与聚对苯二甲酸乙二酯相类似，可看作是由PET链中苯环由刚性更大的萘环所替代的产物。

It can beconcluded from the experimental results that in the reaction of flavonoids withα-hydroxy ethyl peroxyl radicals, 2,3-double bond in the C ring plays a moreimportant role than o-dihydroxy in the B ring.

从实验结果来看，在黄酮类化合物与有机过氧自由基反应的过程中，其分子结构中起主要作用的是C环2，3双键，而不是B环的邻二羟基。

From the photophysical behaviors of 1, 3, 4-triaryl-2pyrazoline compound (TPP16) at low temperature, it can be considered that the twisted configuration between pyrazoline ring and the non-substituted phenyl group on the position 1 is the fluorescence configuration of conjugated system Ⅰ, and the twisted configuration between pyrazoline ring and P-nitrobenzene group is fluorescence configuration of conjugated system Ⅱ.

研究了1，3，4-三芳基-2-吡唑啉化合物TPP16在低温时的发光情况，发现：在低温77K下，共轭体系Ⅰ(苯基-N1-N2＝C3-苯基)在非极性溶剂中不发荧光，在极性溶剂中有较强荧光发射；而共轭体系Ⅱ(N1-N2＝C3-C4＝对硝基苄叉)在非极性溶剂或极性溶剂中均有荧光发射，表明N1所联取代基与吡唑啉环相扭曲的构象是共轭体系Ⅰ的发光构象，而对硝基苄叉与吡唑啉环相扭曲的构象是共轭体系Ⅱ的发光构象。

The contrast experiment shows that the d90 temporary plugging technology presents the best pretection effect,which shield ring intensity is more than 25MPa, the flowback recuperability of the permeability can attain 97.2%, and the shield ring intensity is more than 15 MPa.

进行的对比实验表明，运用&理想充填&理论和&d90&暂堵技术与传统屏蔽暂堵技术相比，&d90&技术对储层有更好的保护效果。该技术对于孔隙性储层屏蔽环强度大于25MPa，渗透率返排恢复率最高能达到97.2%；裂缝性储层屏蔽环强度大于15MPa。

Comparisons between the experimental and computational IR spectra clarify the difference of the open- and closed-ring isomers, which indicate that it is possible to identify the tautomeric form of this diarylethene derivative using a highly selective infrared absorption band and the strong absorption at 1 705 cm-1 of the ring-closed isomer can be used in non-destructive readout by IR light.

通过红外吸收光谱表征了该光致变色二芳基乙烯衍生物在溶液中开、关环前后结构的变化，并采用理论化学计算方法研究了该化合物开、关环异构体的红外吸收振动特性。光致变色异构化过程可以通过红外吸收光谱的变化而识别。关环异构体在1 705 cm

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。