有环的

According to the change of the enemy\'s quantity and the qualitative theory of the differential equation, we research the spruce aphides and its predator system. At the same time, we discussion the spruce aphid multiplication model when the natural enemy quantity is a certain value and the periodic oscillating model whose the quantity of the natural enemy changes along with the time. Obtains the stability condition of the balance point and the limit-cycle existing condition, the system presents the dissipative structure\'s character. Finally it explains that this theoretical analysis has certain practical significance regarding the preventing and controlling harmful insect.

第五章，松毛虫与其天敌的关系是食饵和捕食者的关系，根据天敌数量的变化，利用微分方程定性理论，研究松毛虫与天敌系统，讨论天敌数量为一定时的松毛虫增殖模型和天敌数量随时间变化的周期振荡模型，得到正平衡点全局稳定性和极限环的存在条件，通过计算机模拟，说明周期振荡的捕食模型能够呈现典型的时间耗散结构特征，对于防治害虫有一定的实际意义。

I first saw him walking down the street in San Francisco the following week after hitchhiking the rest of the way from Santa Barbara in one long zipping ride given me, as though anybody'll believe this, by a beautiful darling young blonde in a snow-white strapless bathing suit and barefooted with a gold bracelet on her ankle, driving a next-year's cinnamon-red Lincoln Mercury, who wanted benzedrine so she could drive all the way to the City and when I said I had some in my duffel bag yelled "Crazy!"

我第一次见到他是在旧金山街头（离开圣巴巴拉之后我搭了一趟顺风车一路坐到旧金山，说来没人能信的是，载我的是位穿着件雪白的无吊带泳衣的年轻又可爱的金发美女，她赤着脚，脚踝上还戴着一个金脚环，开着最新款的肉桂色林肯牌"水星"轿车，她还说她想要点安非他命提提神好让她能一路开到旧金山而当我说我的圆筒形行李袋里就有一些的时候她大叫了一声："疯啦！"

Especially Taipei is in globalization and flow space at present, face with new flaneur experience to improve and the culture of the goods amazingly, make the traditional public sphere constructed disappear in the street at the same time, transfer it to with the transition of the consumption culture that mass media bring. Walter Benjamin' urban allegories predicts the kinds of city in the future , is when the city changes and improves most, but today's Xin Yi commercial area is in the city too rapidly while developing, there is a great difference with Paris in the 19th century in one kind of flaneur culture appeared, also break away from the space practice to constructed that traditional flaneur culture in the street, manifest the modern urban flaneur cluture conflict and contradiction in modernity development.

尤其当前台北处於全球化流动空间一环，面临著全新的漫游经验革新与商品文化刺激，同时也使得传统以街道建构的公共领域消失，转为以大众传播所带来消费文化的转型， Benjamin 的城市寓言预测城市未来的样貌，在城市最变动革新的时候，但时至今日的信义商圈同样处在城市急遽发展的时候，所呈现漫游文化样貌却与十九世纪的巴黎有极大的差异，也脱离传统漫游文化以街道建构的空间实践，显现现代城市漫游在现代性发展的冲突与矛盾。

Twilight reigns over it. We perceive vast fluctuations in that fog, a dizzy mirage, paraphernalia of war almost unknown to-day, pendant colbacks, floating sabre-taches, cross-belts, cartridge-boxes for grenades, hussar dolmans, red boots with a thousand wrinkles, heavy shakos garlanded with torsades, the almost black infantry of Brunswick mingled with the scarlet infantry of England, the English soldiers with great, white circular pads on the slopes of their shoulders for epaulets, the Hanoverian light-horse with their oblong casques of leather, with brass hands red horse-tails, the Scotch with their bare knees plaids, the great white gaiters of our grenadiers; pictures, not strategic lines--what Salvator Rosa requires, not what is suited to the needs of Gribeauval.

com 。黄昏将近，千军万马在暮霭中往复飘荡，那是一种惊心动魄的奇观，当时的军容今日已经不可复见了，红缨帽，飘荡的佩剑，交叉的革带，榴弹包，轻骑兵的盘绦军服，千褶红靴，缨络累累的羽毛冠，一色朱红，肩上有代替肩章的白色大圆环的英国步兵和几乎纯黑的不伦瑞克步兵交相辉映，还有头戴铜箍、红缨、椭圆形皮帽的汉诺威轻骑兵，露着膝头、披着方格衣服的苏格兰兵，我国羽林军的白色长绑腿，这是一幅幅图画，而不是一行行阵线，为萨尔瓦多·罗扎①所需，不为格里德瓦尔②所需。

The vivid pictures of a leading jurisconsult''s daily practice which abound in Latin literature —— the clients from the country flocking to his antechamber in the early morning, and the students standing round with their note-books to record the great lawyer''s replies —— are seldom or never identified at any given period with more than one or two conspicuous names.

在拉丁文学中，有大量的关于著名法学专家日常活动的生动描写——从全国各地蜂拥而来的当事人在清晨到达他的接待室，他的学生环立在周围，手里都拿着笔记簿，记录着这伟大法学家的回答——但这样描写的著名人物在任何既定时期内，很少或从来没有超过一个或二个人的。

It is found that: the standard Model can be used to predict flows at the station and resultant velocity and temperature field under some reasonable presumptions; the impact brought by stopcock wind is variable according to the different tunnel structures; the temperature of is related with the distribution of heat load; the VAV system has advantage in energy saving, but when the air volume reduced to a certain degree, we should consider the alteration of rising the temperature of supply air, and increasing the quantity of it.

研究表明：采用合理的假设，标准的湍流模型能够较为准确地模拟和预测地铁站台的温度场与速度场；活塞风对站台的影响随区间形式的不同而不同；空调送风温度的设定与负荷的分布情况有密切的关系；针对站台空调季全天的负荷变化，VAV环控方案可以达到节能的目的，但在风量过小时，适当考虑采用提高送风温度，加大送风量的方法进行局部的调整。

But the people who exercise the quiet Qi Gong can not over stickle for that, lest to hinder the high-level Qi Gong extend. The Regulate breath is effective gentle and relaxes for body and mind of player. It is indispensable element in the full exercise. As to the present day peoples who move restlessly, mind unsettled, heavy pressure, the regulate breath will provide good health protect effect of body, mind and spirit

呼吸的练习对气功练习者是重要的一环，静功练习者却不可过份拘泥，以免妨碍高级气功的锻鍊；而调息对运动员可收身心和缓放松的效果，是完整的运动所不可或缺的；至於躁动不安、心绪不稳定、压力繁重的现代人，调息更有良好的身心灵保健效果。

What usually happens to these two pieces is that the pinion, which has a small cone-shaped end with teeth that fit on the ring, shaves off the ring's teeth and is thus unable to deliver traction to the wheel.

什么通常发生在这两个部分是，小齿轮，它有一个小的圆锥形的牙齿，环形适合，徒弟们把环的牙齿，因此无法提供的牵引力的车轮状结束。

The Yellow River Delta that is one of three most largest estuary delta in China locates an intersect area between the Economy Circle around the Bohai Sea and the Economy Belt of the Yellow River valley. Natural resources like petroleum, natural gas, bittern and terrestrial heat enrich the Yellow River Delta area. Moreover, the natural endow of wetland resources, marine products resources and land resources abound in this area.

黄河三角洲是我国三大河口三角洲之一，地处环渤海经济圈和黄河流域经济带的交汇点，有丰富的自然资源，如石油、天然气、盐卤、地热等，同时具有巨大的湿地资源、丰富的海产资源、广阔的土地资源，土地利用变化剧烈，成为研究土地利用变化的热点地区之一。

Therefore, the choice of single mode in the examination and the frequency-thick band of mode has been given a particular illumination separately in the paper, following a relative numerical simulation. And a multi-cyclical sine signal modulated by Hanning window is used to simulate the excitation wave, and then an inspected ring of nodes is established to receive the echo, finally how the length of the circumferential cracks, the width of the axial cracks and the degree of the thickness-reduce effect the result is explained through the analysis of the result, further more, the reflection factor in the defect has been calculated.

因此，本文也就单一检测模态的选择以及模态频厚积段的选择分别予以了阐述，并有针对性的进行了数值计算：应用Hanning窗调制的多周期正弦波模拟单音频激励信号，并设置监测质点环接收回波，通过分析说明了管道的周向裂纹、轴向裂纹以及点蚀缺陷对缺陷回波所产生的影响，并进一步计算了缺陷处的反射系数。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。