环状的

To analyze and compare the characters of Fuzzy c-Means clustering and artificial immune network aiNet clustering, conclude that Fuzzy c-Means clustering does not work well if the underlying classes or clusters deviate strongly from hyperspherical structures, aiNet is capable of reducing redundancy, describing data structure, including the shape of clusters by experiments on relatively gathering data set, scattering data set, annular data set and corkscrew data set.

分析比较了模糊C 均值聚类算法FCM 和人工免疫网络aiNet 聚类算法的特性，通过它们对相对集中数据、稀疏分散数据、环状和螺旋分布数据聚类来进行比较，得到当遇到潜在的类或簇背离超球面结构时，FCM 算法表现不佳，而aiNet 可以很好的发现数据的内在特征，减少数据中的冗余、描述数据结构和聚类形状，表现良好的适应性。

The light emitted from a Keplerian ring around the objects with strong gravitational field should be affected by Doppler shift, gravitational redshift and deflection of light. The line profiles for a faraway observer are dominated by these effects. In this paper the precise solutions of line profiles for the Keplerian rings in the Schwarz-schild case have been obtained by means of the kinetic equation for photons.

对于一个围绕强引力场物体作开普勒运动的环状发光物，它所发射的光线要受多普勒频移，引力红移和光线偏折等效应的作用，这种作用决定了远处观察者所看到的谱线轮廓，本文利用光子输运方程方法，求出在Schwarzschild度规中的开普勒环所发射的谱线的轮廓的精确解。

Sustained AF could be induced easily in all dogs during vagal nerve stimulation in vivo both before and after isolation of all PVs with encircling lesions created by a bipolar radiofrequency ablation clamp device. PV elimination had no effect on atrial effective refractory period or its responses to cholinergic stimulation. Autonomic ganglia were identified by bradycardic and/or tachycardic responses to high-frequency subthreshold local stimulation. Ablation of the autonomic ganglia overlying all PV ostia suppressed the effective refractory period-abbreviating and AF-promoting effects of cervical vagal stimulation, whereas ablation of only left- or right-sided PV ostial ganglia failed to suppress AF.

无论是在双极环状消融所有PV之前或之后，在体刺激颈迷走神经节过程中持续性房颤在所有犬均能轻易被诱导出，PV切除对心房肌的有效不应期或对胆碱的反应均没有影响，通过对高频的域下刺激发生快速或慢速反应来鉴定自主神经节，消融叠加于PV口部的自主神经节能抑制有效不应期的缩短、和刺激颈迷走神经诱发的房颤促进作用，而仅消融左或右侧PV口部的自主神经节却不能抑制房颤。

While the tissue spaces surrounding a few blood vessels wasAl and Fg positive,no Al or Fg positive cells were observed.In antemortem injurygroup,diffuse subarachnoid hemorrhage,cerebral edema,swelling or pyknotic neu-rons could be observed.The axons showed irregular swelling and disconnection at1～3h,marked swelling and disconnection at 6h,and retraction ball at 15h whichwas more remarkable at 24h after injury.The space between myelin sheaths andaxons was increased at 3～6h after injury.Tortuous and wavelike myelin sheathswhich adhered on axons incompletely,or even peeled off could be found from 15hto 24h after injury.Perinuclear lysis of Nissl bodies began at 24h after injury.Thenumber of GFAP positive cells in cerebrum and brain-stem increased significantlyfollowed by decrease,and then increased again,but the time courses of the changesin different areas of brain were not same.Al and Fg positive neural cells,mainlysurrounded blood vessels,with diffuse or peripherally distributed positive matter incytoplasm could be observed at 0.5h after injury.The number of Al or Fg positivecells and the intensity of immunoreaction increased with the time of injury.The areaof SYN positivity in medulla oblongata and pons decreased notably 3～6h afterinjury,then return to normal levels and continued to 24h after injury.

生前损伤组，可见广泛蛛网膜下腔出血，脑组织水肿，神经细胞肿胀，晚期神经元固缩；伤后1～3h见部分神经轴突不规则增粗、断裂，伤后6h断端膨大，伤后15h可见收缩球，至伤后24h更为明显；伤后3～6h可见部分神经髓鞘与轴突之间的间隙增宽，伤后15h髓鞘明显曲折，不完全附着在轴突两侧，甚至剥脱，持续到伤后24h；核周尼氏体减少在伤后24h才开始出现；同一部位的GFAP阳性细胞数目随损伤时间发生改变，先增多（最早在伤后0.5h），达到高峰后减少，其后又有增多趋势，但不同部位的GFAP阳性细胞数目增减的时间过程不尽相同，同时，大脑中的GFAP阳性细胞数目也有改变；伤后0.5h，可在脑干组织中见到Al和Fg阳性神经细胞，主要位于血管周围，阳性物在胞浆中呈弥散性分布，但部分细胞的阳性物仅分布于靠近胞膜的胞浆中而呈环状，随损伤时间延长，阳性细胞数目增多，反应强度增加；伤后3～6h，延髓及桥脑中的SYN阳性物面积减少，其后恢复到正常水平，并持续到伤后24h。

Thus, the Puritan elders, in their black cloaks, starched bands, steeple-crowned hats, smiled not unbenignantly at the clamour rude deportment of these jolly seafaring men; it excited neither surprise nor anim-adversion, when so reputable a citizen as old Roger Chillingworth, the physician, was seen to enter the market-place, in close familiar talk with the commander of the questionable vessel.

因此 www.8 t tt8。 com ，那些穿着黑色礼服、挺着浆过的环状皱领、戴着尖顶高帽的清教徒长者们，对于这帮快活的水手们的大声喧哗和粗野举动，反倒报以不无慈爱的微笑；而当人们看到老罗杰·齐灵渥斯这样一个德高望重的居民和医生走进市场、同那艘形迹可疑的船只曲船长亲密面随便地交谈的时候，既没有引起惊讶之感，也没有议论纷纷。

The plasma arc generator comprises cathode, two anodes and insulating strip between two anodes, first anode is cylindrical hollow sleeve, the cylinder cathode is placed in the centre of said sleeve, and an annular fluid channel is formed between both the lower portion of first anode is equipped with a hole as fluid outlet, and second anode is a circular plate with central hole, between two anodes there is an insulating strip, the diameter of central hole of second anode is less than the diameter of lower hole of first anode.

本发明是一种串式多级压缩等离子弧发生器，由阴极、两阳极及阳极之间的绝缘片组成，第一阳极为圆柱形空心套管，圆柱体阴极处于该套管中心，并在两者之间形成环状流体通道，第一阳极下部是一个供流体出口的横截面为圆的孔，第二阳极是中心开孔的圆形板，两阳极之间有绝缘片，第二阳极中心孔的直径小于第一阳极下部孔的直径。

Cyclodextrins, cyclic oligosaccharides commonly composed of six, seven or eight respectively D-glucopyranosyl units connected by α-(1, 4)-glycosidic linkages, have the ability to form inclusion complexes with a wide range of substrates for their particular structures. With proper rigidity and flexibility, excellent mechanical stability and biocompatibility, cyclodextrins are good choice of material in molecular imprinting technology.

环糊精是由六，七或八个D-吡喃葡萄糖单元通过α-1，4 糖苷键连接成的环状低聚糖，由于其特殊的结构使其可以包结一系列的底物，加之具有适当的刚性、柔性、机械稳定性，良好的热稳定性和生物相容性等使其成为分子印迹技术优秀的选择材料。

The main structure of Phenolic resin curing is a three-dimensional network linked by methylene between phenols.It is shown in the process of thermal degradation that the thermal degradation of phenols and methylenes,and degradation product of gas small-molecule is a little;While the character of the epoxy resin molecule structure is that the milecule chains contain lively epoxy group,which can be at the end ,middle of the molecule or forms rings structure.

酚醛树脂固化物的主要结构为苯酚之间通过亚甲基连结的一种三维体型网络，因此在热降解过程中主要表现为酚基和亚甲基的热降解，降解后气态小分子产物很少；而环氧树脂的分子结构是以分子链中含有活泼的环氧基团为其特征，环氧基团可以位于分子链的末端、中间或成环状结构。

Ruptured aneurysms may have high density blood in basal cisterns and sulci adjacent to them, in addition to subarachnoid hemorrhage.

破裂的动脉瘤可能在基底池及邻近脑沟内有高密度出血，未破裂的动脉瘤伴有部分或完全的血栓可以表现为稍高密度影，常常会有环状钙化壁或附壁血栓，增强扫描，伴有部分血栓的动脉瘤最特异的表现是靶征，完全血栓形成的动脉瘤可以有反应性的边缘强化，没有血栓形成的动脉瘤表现为明显均匀性管腔样强化。

The distribution of ATPase activity in the phloem parenchyma cells and flesh parenchyma cells(no-phloem parenchyma cells)changed during the different developmental phases of the fruit.It isparticularly interesting to observe a band along the plasmalemma of flesh parenchyma cellsadjacent to the phloem,the band highly enriched with the ATPase activity,forming a ring ofencirclement that surrounds the phloem.

结果表明：SE/CC复合体的ATP酶主要定位于质膜上，韧皮薄壁细胞和果肉薄壁细胞的ATP酶在不同时期的分布和活性是不一样的，令人注目的是：在邻近韧皮部的果肉库细胞的细胞壁和质膜之间发现一条ATP酶活性物质的聚集带，形成环状，包围韧皮部。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐