环

Within this study, we found some interesting results, for example, the type of ring opening mode of methylene cyclopropyl ketones was changed from distal to proximal under the catalysis of palladium with the addition of two equivalents of sodium iodide.

我们发现了一个非常有趣的现象：亚甲基环丙烷基酮的开环方式可以得到有效的调控：在没有外加卤离子的情况下，开环方式为distal断裂，从而得到了4—氢吡喃化合物，而在两当量的碘化钠的存在下却发生了proximal断裂，从而能够得到2，4—双取代的呋喃。

The results showed that hydrogen peroxide, silanols species and TiO〓 didn't have solvolysis activity of propylene oxide. While framework Al, coordinatively unsaturated Ti〓 ions as Lewis acid sites in the framework, Ti-OH and the five member ring active titanium species formed by TS-1, hydrogen peroxide and solvent can catalyze the solvolysis of propylene oxide.

研究结果表明：原料双氧水和TS-1沸石上的SiOH和TiO〓对环氧丙烷溶剂解反应无催化活性；而下列物种对环氧丙烷溶剂解反应具有催化活性：TS-1中的骨架铝，沸石骨架中配位不饱和的Ti〓形成的L酸中心，TS-1水解产生的钛羟基和由TS-1，双氧水和溶剂相互作用所生成的五元环中间活性钛物种。

Liquid-phase epoxidation of allyl chloride with hydrogen peroxide was carried out over Ti-MWW, a novel titanosilicate with the MWW structure, to synthesize epichiorohydrin selectively and effectively. Ti-MWW proved to be superior to the conventional TS-1 catalyst in both catalytic activity and product selectivity. Ti-MWW prefers aprotic solvents of acetone and acetonitrile, both of which can restrain the solvolysis of epichiorohydrin, whereas TS-1 favors a protic solvent of methanol.

研究了具有MWW结构的新一代钛硅分子筛Ti-MWW催化剂对烯丙基氯液相环氧化高效合成环氧氯丙烷的催化性能结果表明，Ti-MWW的催化活性以及产物选择性均优于传统的钛硅分子筛TS-1，对于Ti-MWW，合适的溶剂为非质子性溶剂丙酮和乙腈，在该溶剂中环氧化物不易发生溶剂化开环反应；而对于TS-1，合适的溶剂是质子性溶剂甲醇，但甲醇可导致醇醚副产物的生成。

The provided PCRR also satisfies the well-known relationship between free spectral range and ring radius R of traditional micro-strip ring resonators.

运用经典的微环自由光谱范围FSR和微环半径R的关系，证实新型的光子晶体微环腔也满足该关系。

In this paper,the concept of ideal of ring is spreaded by widening the satisfying conditions of the subring of ring,thus the concept of weak nearly-ideal is drawn out,and several basic properties of weak nearly-ideal are given.

通过对环的子环所满足的条件进行加强，推广了环的理想概念，引入了弱近理想的概念，讨论了弱近理想的性质，以及弱近理想与近理想、理想、弱理想的关系。

The present paper presents a short proof of the conjecture that a ring with a finite maximal subring is a finite ring.

摘要给出猜测"包含有限极大子环的环是有限环"的一个简短证明。

Central part of the water on the inner surface just tangent with the impeller wheel, water ring coincides with the lower part of the inner surface contacts the top leaves (the leaves in the water in fact has a certain ring insertion depth).

水环的上部分内表面恰好与叶轮轮毂相切，水环的下部内表面刚好与叶片顶端接触（实际上叶片在水环内有一定的插入深度）。

The next part of the water ring coincided with the inner surface of the impeller wheel Tangent, water ring coincides with the inner surface of the upper leaves of the top contact (in fact the leaves in the water ring must have the insertion depth).

水环的下部分内表面恰好与叶轮轮毂相切，水环的上部内表面刚好与叶片顶端接触（实际上叶片在水环内有一定的插入深度）。

Water rings on the part of the inner surface just tangent with the impeller wheel, water ring coincides with the lower part of the inner surface contacts the top le**es (the le**es in the water in fact h**e a certain ring insertion depth).

水环的上部分内表面恰好与叶轮轮毂相切，水环的下部内表面刚好与叶片顶端接触（实际上叶片在水环内有一定的插入深度）。

Since China entered WTO,especially since from 2007,China's foreign trade environment has gotten great changes:domestically,foreign trade policies adjust, duty draw-back decrease,RMB increase in value sustention,new labor law takes effect,internationally,the states arose serious Supreme Mortgage Crisis which further caused financial crisis,euramerican countries impose technique barrier and enhance protectionism;under such harsh situation,what course to follow puzzle personnel of medium and small foreign trade enterprises.

自从加入WTO到现在，特别是从2007年起到现在，我国的外贸环境发生了很大变化：国内方面，外贸政策调整，出口退税减少，人民币持续升值，新的劳动法的实施等等；国际方面，美国发生了严重的次贷危机，以及由此引发的金融危机，欧美国家实行的技术壁垒和日益严重的保护主义；在此种严峻形势下，我国的外贸出口企业何去何从，困扰着广大企业人员。本文应用SWOT理论，对AB外贸公司的内外环境进行了分析，从全球价值链高环介入的方面，进一步提出了AB外贸公司应该提升在价值链中的地位的战略，改变低环介入价值链的方式，逐步转变为从高环介入，核心思想是要提高外贸企业的核心竞争力。

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。