多旋回

These cycles plus two first-order cycles in the Phanerozoic successions have disclosed that a genetic link may be postulated for individual Earth shells and galactic precessional cycles.The stratigraphic records of the above-mentioned cycles are significant especially for the division of the Precambrian strata with lower stratigraphic resolutions.

尽管对地层记录中隶属不同级别沉积层序的间断面所代表的间断时限的绝对年限还难以精确估价，而建立在岩相及相序基础之上的旋回性地层记录的研究，是从复杂而不完整的地层记录中寻找出更多规律性的有效途径，特别是对生物地层分辨率不高的前寒武纪地层，尤其显得更加重要。

Many sparsely disseminated and nodular pyrite can be found in the oil shales. With the oil shale occurring in the bottom, trona, salt, dolomite and silty mud rock also the oil shale make up many sedimentary rhythms.

其内可见大量星点状、结核状黄铁矿，并作为天然碱矿层的直接底板与天然碱、盐岩、白云岩及粉砂质泥岩构成了多个韵律旋回。

Carbonate fractured/caverned karst reservoirs are a kind of composite ones that are superimposed by many fracture/cavern units within the control of cyclical tectonics and karstification so this kind of reservoirs are more difficult exploration and development than other kind of ones.

碳酸盐岩岩溶缝洞型油气藏是受构造—岩溶旋回作用控制、由多个缝洞单元在空间上叠合形成的复合油气藏，勘探开发难度比较大。塔河油田是我国第一个以奥陶系碳酸盐岩岩溶缝洞型油气藏为主的古生界海相大油气田，勘探开发有其特殊性和复杂性。

Study shows that environment evolution and eustatic change of Holocene in this area may be divided into 6 stages:① early stage of early Holocene, 9 100~10 900 aBP,when sea level was low and this area was an oxidizing environment or oxidizing-reducing transition environment;② late stage of early Holocene, 8 000~9 100 aBP, sea-level rising,...

研究表明，本区全新世环境演化分为6个阶段：①早全新世早期，10900~9100aBP，海平面较低，尚未淹没本区，为近岸氧化环境或氧化—还原过渡环境；②早全新世晚期，9100~8000aBP，海水上涨，本区时淹时退，为浅海或潮坪环境，生物钻孔发育；③中全新世主体，8000~4150aBP，海平面快速上升，完全淹没，Fe2+/Fe3+介于0.7395~1.9123之间，为全新世中最高段，表明还原程度强、全球气候变暖；④中全新世后期，4150~2850aBP，海水有所下降，仍为浅海环境，Fe2+/Fe3+较高，多在1.0以上；⑤晚全新世，2850~1310aBP，海平面进一步下降，本区时常暴露，其中2150~1310aBP以还原环境为主，为潮下带，2150~2850aBP以氧化—还原过渡环境为主，为潮间带；⑥1855AD以来，海平面基本稳定，稍有上升，为现代黄河三角洲沉积时期。本区全新世至少存在5期冷热交替的旋回性气候变化。

Methods:The magnetic resonancestudies were performed in the 14 patients with non myxomatous cardiac and pericardial tumors with the spin echo and cine pulse sequence.

收集经手术病理证实的原发性非粘液瘤性心脏心包肿瘤 14例，行 MRI自旋回波多体位扫描及磁共振电影检查。

On the basis of an integrated analysis of the geochemical features of these volcanic rock associations,this paper concludes that thebasalts originated mainly from interaction between mantle-derived magma and low-crustal materials, and rhyolitic volcanic rocks resulted from thermal and chemical interaction between basaltic magma and the upper part of crustal materials.Basalts and rhyolites in different cycles have different source regions,and they are products of multiperiodic pulsive layer partial melting.

根据对火山岩地球化学特征的综合分析表明，玄武岩主要为幔源岩浆与下部地壳岩石相互作用的产物，而流纹岩则为玄武岩浆与上部地壳物质进行热及成分交换的结果，不同旋回的玄武岩和流纹岩有不同的源区，为多次脉动分层部分熔融的产物。

Increased amplitude also results in sea level falling faster than flats can subside, so that disconformities with thick vadose profiles develop.

海平面振荡幅度的增加也能造成海平面下降快于潮坪的沉降，滨线向海迁移速率比潮坪进积的速率要快得多，从而在旋回层序内发育较厚的渗流带以及不整合界面。

There are three sedimentary cycles developed in each basin, relating to three times of deepening and shoaling of the lake.

每个盆地基本上都发育三个沉积旋回，经历了三次湖盆加深、变浅的过程，后期多被火山岩覆盖。

Multiple-set oil-generation series of strata being of different geologic-geochemical characteristics were formed because of the staging property of the filling and evolution of Lower Tertiary lake basin and the cyclicity of sedimentary proce...

下第三系湖盆充填演化的阶段性和沉积过程的旋回性，形成了多套具有各自地质地球化学特征的生油层系。

Generally, topspin returns should be deep on the table; in fact, deep and less spinny is usually better than shorter and more spinny.

一般来说，上旋回球应该深，事实上，深且少些旋转通常比短些且旋转多些更好。

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