弧长 - 网络例句 - 英语人，englisher

The point of a line segment or curvilinear arc that divides it into two parts of the same length.

中点一条线段或一段弧上的一点，该点将此线段或弧平分为等长的两部分

Type IB: Isocline is convergent towards inner arc at a right angle to the fold.

根据等斜线的收敛层度，再细分为三个亚型：IA型：等弧线向内弧强烈收敛，各线长短判别极大，内弧曲率远大于外弧曲率，为典型的顶薄褶皱；IB型：等倾斜线向内弧收敛，并与褶皱面垂直，各线长短大致相等，褶皱层真厚度不变，内弧曲率仍大于外弧曲率，为典型的平行褶皱；IC型：等斜线相内弧轻微收敛，转折端等倾斜线比两翼附近的要略长一些，反应两翼厚度有变薄的趋势，内弧曲率略大于外弧曲率。

And the late Triassic bimodal association reflects the characteristics of intracontinental rift setting, the early Jurassic Raohe ultramafic - mafic rock - pillow lava association represent the environmental characteristics of oceanic island, magmatic arc association represent the characteristics of island arc and active continental margin with the background of the plate subduction, middle Jurassic syn-orogenic granodiorite-granite association reflects characteristics of matching and orogensis after continental accretion.

其中晚三叠世双峰式组合反映了板内裂谷成因特征，早侏罗世饶河超镁铁质-镁铁质岩-枕状熔岩组合代表了洋岛环境特征，岩浆弧火成岩组合代表了板块俯冲背景下岛弧和活动大陆边缘特征，中侏罗世同造山花岗闪长岩-二长花岗岩组合反映了陆缘增生后拼贴造山的成因特点，它们总体上代表了由被动陆缘裂向活动陆缘转化并最终发生陆缘增生带拼贴造山的一个演化过程，其间伴随有被动陆缘深海盆地沉积、活动陆缘弧后前陆盆地沉积和陆相类磨拉石建造

Of the five stages deformation, the exact ages of the (2) and (3) were determined by 40Ar/39Ar method as 290 and 259 Ma respectively.2. New results on the metamorphic belts and associated metamorphism of the Xiaopu metamorphic rocksBased on detailed microtextural observations and occurrence of typical metamorphic minerals, five metamorphic belts in the Xiaopu metamorphic rocks are identified. From the north to the south, they are biotite belt, garnet belt, staurolite belt, andalusite belt, and sillimanite belt. I suggested that the metamorphic belts occurred in the Xiaopu area belongs to the high temperature/low pressure series, may have resulted from the later Permian crust extension at ca. 290 Ma.3. I suggest that there may have been a Carboniferous backarc basin along the southern slope of the Harlik Mountain.Detrital Zircon SHRIMP U-Pb dating indicated that the sedimentary age of the Julideneng formation lithic sandstone must be later than late Devonian, most likely is Carboniferous rather than previously thought Precambrian. Analyses on its geologic setting, location of provenance, and sedimentary environment suggest the Carboniferous strata may form in a lagged backarc basin bounded by backarc uplifts.5. Reconstruction of the post-Paleozoic tectonic evolution history of the Harlik MountainThe tectonic evolution of Harlik mountains since the Paleozoic were reconstructed as followings:(1) arc-affinity magmative activities occurred during the middle-Ordovician to early-Silurian;(2) the middle-Silurian to late-Devonian was a back-arc uplift stage;(3) back-arc extension featured the Carboniferous period;(4) post-collisional extension and/then compression during Permian;(5) at the Mesozoic, differential uplift developed; and (6) the late Cenozoic is the intra-continental re-orogen stage.6. Primary estimation of the crust shortening is madeThe folded pre-Mesozoic strata were used to estimate crust shortening along the Harliknanshankou-Koumenzi, Shichengzi-Baishitou, and Qincheng-Xiaopu sections. Their shortening ratios are 16.2%, 19.8%, and 20.1% respectively corresponding crust shortening are 4.3, 9, and 11.3 km.

根据Ar-Ar热年代学研究，精确测定了早二叠世伸展变形和晚二叠世挤压变形的峰期时代分别为290Ma和259Ma.2、提出了关于哈尔里克山南麓小铺一带变质带和变质作用的新认识根据显微观察资料和特征变质矿物的出现，把小铺一带的变质岩由SW向NE方向依次划分为黑云母带、石榴石带、十字石带、红柱石带和矽线石带等变质带；初步确定该区的变质作用属于中温-低压型，变质作用发生的时代为290Ma左右，是该区早二叠世地壳伸展的产物。3、首次提出哈尔里克山南麓在石炭纪可能发育弧后盆地的新观点根据哈尔里克山南麓原"居里得能组"岩屑砂岩的碎屑锆石SHRIMP U-Pb定年，确认这套地层的沉积不早于晚泥盆世，很可能是石炭纪，而不是前人所说的前寒武纪；结合对其区域地质背景、源区位置和沉积环境分析，推测该区石炭纪可能为滞后弧后盆地和弧后隆起区构造背景。4、进一步证明哈尔里克山不发育与岛弧演化相关的泥盆纪岩浆活动根据对代表性闪长岩和花岗岩的锆石SHRIMP年代学研究获得的新资料，结合该区已有相关资料的综合研究，确定哈尔里克山岩浆岩分别形成于奥陶纪-志留纪和石炭纪晚期-二叠纪，不存在泥盆纪的岩浆岩，进而认为该区泥盆纪不属于岛弧环境。5、重建了哈尔里克山古生代以来的地质演化过程根据区域资料以及本次研究所获得的资料，把哈尔里克山古生代以来的构造演化划分中奥陶世-早志留世为岛弧、中志留世-晚泥盆世为弧后区、石炭纪弧后伸展、二叠纪为后碰撞伸展与挤压、中生代差异隆升和晚新生代陆内再造山过程等构造阶段。6、初步估算了哈尔里克山地壳缩短率和缩短量根据前中生代地层褶皱估算的哈尔里克山南山口-口门子、石城子-白石头和沁城-小铺三条剖面的地壳缩短率分别为16.2%、19.8%和20.1%，相应的地壳缩短量分别为4.3km、9km和11.3km。

Neoproterozoic Baoxing Complex in middle to lower metamorphic grade, located in western margin of Yangtze Craton, consists mainly of metamorphic gabbroic, dioritic gneisses, tonalitic and granodioritic gneisses, and massive monzogranites The studies of petrochemistry and SmNd isotopes of Baoxing Complex reveal that the gabbroic and dioritic magmas came from a congenetic magma derived from the partial melting of spinel lherzolites in depletive mantle, and that the magma was intensively contaminated by crustal materials during its emplacement The tonalitic and granodioritic magma were derived from the partial melting of metamorphic basalts in the lower crust And the monzogranitic magma was formed from partial melting of metagreywacks Integrating the lithological association, their trace elements, SmNd isotopic characteristics and petrogenesis, the Baoxing Complex must likely have been emplaced in an island arc tectonic background at the Neoproterozoic active continental margin of Yangtze Craton

位于扬子克拉通西缘的新元古代宝兴杂岩主要由中低级变质的辉长质片麻岩、闪长质片麻岩、英云闪长质到花岗闪长质片麻岩和块状二长花岗岩组成。岩石地球化学和SmNd同位素特征表明，辉长质片麻岩和闪长质片麻岩为同源岩浆演化序列，原始岩浆起源于亏损地幔尖晶石橄榄岩的部分熔融，在上升和侵位过程中受到了地壳岩石强烈混染。英云闪长质和花岗闪长质岩浆形成于下地壳玄武质岩石部分熔融，而二长花岗质岩浆形成于杂砂岩的部分熔融。综合分析宝兴杂岩的岩石组合、微量元素和同位素特征，该杂岩体最有可能形成于新元古代活动大陆边缘火山弧构造背景，并可能经历了碰撞过程。

The Paleoproterozoic Beidahe Group-complex remains as continental shivers in the interior of the North Qilian orogen. In its early stage of development, there occurred abundant amphibolite. The protolith of the amphibolite is basalts. The Alk-∑FeO-MgO plot, REE features and Rittmann index show that the protolith belongs to the calc-alkaline suite and exceptionally shows the subalkaline character. The rock is characterized by higher Al2O3 and ∑FeO and lower Mg#, indicating that it has a higher degree of compositional evolution and that the formation of volcanic rocks is related to activation of older crust. Highly fractionated REE patterns and amphibolite on the Ti-Zr-Y plot, Ni-FeO/MgO plot and Ta/Yb-Th/Yb plot all indicate the characteristics of volcanic arcs and active continental margins. On the geochemical diagram of basalt, the overall REE features are in the main analogous to those of calc-alkaline island-arc basalt, with Sr87/Sr86=0.71617–0.72033,Nd143/Nd144=0.512414–0.512495 and εNd=–2.79 to –4.37,εSr=245.78–305.3, showing that the magma was derived from the crust or subjected to contamination with the lower crust below the continent.

提要：以大陆碎块形式残存于北祁连造山带内部的古元古代北大河岩群早期发育有大量的斜长角闪岩，其原岩为玄武岩，Alk—∑FeO—MgO图解，REE特征，里特曼组合指数等均显示斜长角闪岩属钙碱性系列范围，个别显示弱碱性，斜长角闪岩具有较高的Al2O3，∑FeO和低的Mg#，这些特点反映其成分演化程度较高，表明火山岩的形成与古老地壳的活化有关，有较强分异的稀土元素分配模式，在Ti—Zr—Y图，Ni—FeO/MgO图解和Ta/Yb—Th/Yb图解上斜长角闪岩均显示火山弧或活动大陆边缘的特点，在玄武岩的地球化学形式图，稀土元素整体特征与钙碱性岛弧玄武岩基本相同；87Sr/86Sr=0.716 17～0.720 33， 143Nd/144Nd=0.512 414～0.512 495，εNd=-2.79～-4.37。

In the K-Na-Ca diagram, intermediate part has the tendency of toellite, and acid part has the tendency of calc-alkaline. According to the above data, its tectonic setting is thought to be continental arc.

其序列组成为石英闪长岩－花岗闪长岩／斜长花岗岩／英云闪长岩－二长花岗岩组合，二长花岗岩略多，地球化学特征具典型造山花岗岩特征，K-Na-Ca图解中性段具英云闪长岩趋势，酸性段呈钙碱性趋势，其构造坏境为大陆弧。

It was indicated by theories and experiments that as a new type spiral bevel gear transmission, double circular arc spiral bevel gearing has the advantage of higher load capacity, longer service live, smaller volume, lighter weight and higher transmitting efficiency etc. Therefore, more and more attention has been paid to its application and research in recent years.

理论和实验研究表明，作为一种新型弧齿锥齿轮传动方式，双圆弧弧齿锥齿轮传动具有承载能力高、使用寿命长、体积小、重量轻、传动效率高等特点，所以对它的应用和研究日益受到人们的重视。

Aerators are widely used in flood discharge tunnel s and spillways to prevent the cavitation damage of the structures.

对高水头、大单宽流量、低佛氏数、小底坡长明流泄洪洞，在反弧段末端采用常规的掺气坎往往难以取得理想的掺气效果，同时，反弧段下游边墙易出现空蚀破坏。

Of the five stages deformation, the exact ages of the (2) and (3) were determined by 40Ar/39Ar method as 290 and 259 Ma respectively.2. New results on the metamorphic belts and associated metamorphism of the Xiaopu metamorphic rocksBased on detailed microtextural observations and occurrence of typical metamorphic minerals, five metamorphic belts in the Xiaopu metamorphic rocks are identified. From the north to the south, they are biotite belt, garnet belt, staurolite belt, andalusite belt, and sillimanite belt. I suggested that the metamorphic belts occurred in the Xiaopu area belongs to the high temperature/low pressure series, may have resulted from the later Permian crust extension at ca. 290 Ma.3. I suggest that there may have been a Carboniferous backarc basin along the southern slope of the Harlik Mountain.Detrital Zircon SHRIMP U-Pb dating indicated that the sedimentary age of the Julideneng formation lithic sandstone must be later than late Devonian, most likely is Carboniferous rather than previously thought Precambrian. Analyses on its geologic setting, location of provenance, and sedimentary environment suggest the Carboniferous strata may form in a lagged backarc basin bounded by backarc uplifts.5. Reconstruction of the post-Paleozoic tectonic evolution history of the Harlik MountainThe tectonic evolution of Harlik mountains since the Paleozoic were reconstructed as followings:(1) arc-affinity magmative activities occurred during the middle-Ordovician to early-Silurian;(2) the middle-Silurian to late-Devonian was a back-arc uplift stage;(3) back-arc extension featured the Carboniferous period;(4) post-collisional extension and/then compression during Permian;(5) at the Mesozoic, differential uplift developed; and (6) the late Cenozoic is the intra-continental re-orogen stage.6. Primary estimation of the crust shortening is madeThe folded pre-Mesozoic strata were used to estimate crust shortening along the Harliknanshankou-Koumenzi, Shichengzi-Baishitou, and Qincheng-Xiaopu sections. Their shortening ratios are 16.2%, 19.8%, and 20.1% respectively corresponding crust shortening are 4.3, 9, and 11.3 km.

根据Ar-Ar热年代学研究，精确测定了早二叠世伸展变形和晚二叠世挤压变形的峰期时代分别为290Ma和259Ma.2、提出了关于哈尔里克山南麓小铺一带变质带和变质作用的新认识根据显微观察资料和特征变质矿物的出现，把小铺一带的变质岩由SW向NE方向依次划分为黑云母带、石榴石带、十字石带、红柱石带和矽线石带等变质带；初步确定该区的变质作用属于中温-低压型，变质作用发生的时代为290Ma左右，是该区早二叠世地壳伸展的产物。3、首次提出哈尔里克山南麓在石炭纪可能发育弧后盆地的新观点根据哈尔里克山南麓原&居里得能组&岩屑砂岩的碎屑锆石SHRIMP U-Pb定年，确认这套地层的沉积不早于晚泥盆世，很可能是石炭纪，而不是前人所说的前寒武纪；结合对其区域地质背景、源区位置和沉积环境分析，推测该区石炭纪可能为滞后弧后盆地和弧后隆起区构造背景。4、进一步证明哈尔里克山不发育与岛弧演化相关的泥盆纪岩浆活动根据对代表性闪长岩和花岗岩的锆石SHRIMP年代学研究获得的新资料，结合该区已有相关资料的综合研究，确定哈尔里克山岩浆岩分别形成于奥陶纪-志留纪和石炭纪晚期-二叠纪，不存在泥盆纪的岩浆岩，进而认为该区泥盆纪不属于岛弧环境。5、重建了哈尔里克山古生代以来的地质演化过程根据区域资料以及本次研究所获得的资料，把哈尔里克山古生代以来的构造演化划分中奥陶世-早志留世为岛弧、中志留世-晚泥盆世为弧后区、石炭纪弧后伸展、二叠纪为后碰撞伸展与挤压、中生代差异隆升和晚新生代陆内再造山过程等构造阶段。6、初步估算了哈尔里克山地壳缩短率和缩短量根据前中生代地层褶皱估算的哈尔里克山南山口-口门子、石城子-白石头和沁城-小铺三条剖面的地壳缩短率分别为16.2%、19.8%和20.1%，相应的地壳缩短量分别为4.3km、9km和11.3km。