环

Results: In all 13 patients, non-contact mapping showed AFLs confined to the RA with the cycle length (230 ±20 ms). 6 patients presented single-loop re-entry circulating around the central obstacle in the anterolateral wall through the channel between the CO and the crista terminalis .Seven patients presented "8" re-entry, and the gap of upper and lower loop located in CT in 4 cases, another 3 cases with upper loop and free-wall single-loop re-entry. RF of CT gap and/or the free-wall channel was effective in eliminating these AFLs in 13 patients.

结果 经 NMS标测证实13例患者折返均在右房内，激动在右房内的折返平均时间为230±20ms.6例房扑患者为单折返环，围绕右房中心障碍区折返，激动在心房的前壁穿过中心障碍区与界瘠之间的狭窄通道。7例患者证实为2个折返环，其中4例表现为上下折返环形成"8"字形折返，共同的传导通道在界瘠；另外3例表现为折返环1个在心房上部，1个在前游离壁。13例消融界瘠或前游离壁后房扑终止。

The commercial processes of cyclohexane oxidation to cyclohexanone and cyclohexanol generally show many problems, such as low conversion, poor selectivity, complicated technology, high-energy consumption and environmental pollution. So it seems to be of great academic and practical interesting to study and develop highly efficient and environmentally friendly catalytic cyclohexane oxidation processes.

现有的环己烷氧化制环己酮和环己醇生产工艺普遍存在转化率低、选择性差、工艺复杂、耗能大和对环境污染严重等问题，这就使得研究和开发高效、环境友好的环己烷催化氧化工艺具有重要的理论意义和实用价值。

Ervertebralis of scoliosis goat apical vertebral,there is no significant difference in distribution of any two sections' sympathetic fiber in normal peoples annulus fibrosus disci intervertebralis,and there is significant difference between the sympathetic fiber distribution of convex side and concave side in annulus fibrosus disci intervertebralis of AIS apical vertebral-the sympathetic nerve supply of convex side to gain advantage concave side.

结果成功构建山羊脊柱侧凸模型，研究发现正常山羊椎间盘纤维环四个区的交感神经分布无显著差异；侧凸山羊顶椎区椎间盘凸凹侧纤维环交感神经分布无显著差异；正常人椎间盘纤维环四个区的交感神经分布无显著差异；青少年特发性脊柱侧凸患者顶椎区椎间盘凸凹侧纤维环交感神经分布有显著差异，凸侧明显多于凹侧。

Our results show that the duality of self-dual tetrahedral link is "trivial", and the duality of hexahedral and octahedral link as well as dodecahedral and icosahedral link are "nontrivial".

从构型角度考虑，四面体链环的自对偶是"平凡"的，六面体链环和八面体链环，十二面体和二十面体链环的对偶是"非平凡"的。

In section one, we study regular cu-rings by use of full elements in rings, and give some equivalent conditions for the endomorphism ring of quasi-projective modules and quasi-injective modules to be a cu-ring.

在第一部分，我们利用环中的完全元对正则cu-环进行刻画，并给出了拟投射模和拟内射模的自同态环是cu-环的一系列等价条件。

We build the model for the enveloping worm helix parametric equation and then analyze its relations with the enveloping worm helix tooth surface equation,thus establishing the characteristic model of the involute helicoid enveloping worm′s generative gears.

渐开面环面蜗杆的三维构建属复杂曲面造型，文章在环面蜗杆螺旋线参数方程建模的基础上，分析讨论了其与渐开面环面蜗杆螺旋齿面方程的对应关系，建立了渐开面包络环面蜗杆产型齿的特征模型。

In this chapter, firstly, the definition of rough rings and its properties are given. Then the definition and properties of rough subrings, rough ideals and rough quotient rings are put forward and proved. Finally, homomorphism and isomorphism of rough rings is studied.

在这一章中，首先给出了粗糙环的定义及其性质，其次给出了粗糙子环、粗糙理想、粗糙商环的定义及其性质，最后研究了粗糙环的同态与同构。

In 1977, Nicholson introduced the concept of clean rings as follows: A ring R is said to be clean ring if every element of R is the sum of an idempotent element and an invertible element.

Nicholson引入了一种新的环类，即所谓的clean环：一个环$R$被称为clean环，如果$R$中的任意一个元素均可以表示成R中一个幂等元和一个单位和的形式。

Based on the needs of system control strategy and the output of the active inverter, a switch function method was adopted to build the average model of switch cycle for the active inverter in order to accurately analyze operation characteristic of active inverter, a feed forward and double loop control strategy is put forward, its double control includes a inductor current inner loop control and instantaneous voltage outer loop control.

中文摘要：为准确分析有源逆变器的运行特点，根据系统控制策略的需要，在考虑了有源逆变器输出的基础上采用开关函数法建立了有源逆变器的开关周期平均模型。提出一种前馈加双环控制的控制策略，它的双环控制包括一个电感电流内环控制和一个瞬时电压外环控制。

To facilitate the restoration and recovery of reef ecosystems and to protect the marine resources, the government of Taiwan ROC has designated Dongsha Atoll as a marine national park in March 2004. The area encircled by 100 m isobath has been designated as the protected zone and the area encircled by 12 miles from the edge of the atoll has been declared as the general control zone.

为了保护东沙环礁的生物资源及促进环礁生态系的复原，政府已於2004年3月通过设立东沙国家海洋公园，预定将环礁外围100公尺等深线之内的范围划设为海洋生态保护区，此界限至环礁外围12里为一般管制区。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。