向后投影

Fourthly,a Fast Back Projection algorithm is presented.It sloves the problem of large computational load of BP algorithm and the condition of dividing the subapterture is presented.

接着提出了一种快速后向投影算法，解决了BP算法计算量大的问题，给出了子孔径划分的条件。

Its universality: its democratic equality and constancy to its nature in seeking its own level: its vastness in the ocean of Mercator's projection: its unplumbed profundity in the Sundam trench of the Pacific exceeding 8000 fathoms: the restlessness of its waves and surface particles visiting in turn all points of its seaboard: the independence of its units: the variability of states of sea: its hydrostatic quiescence in calm: its hydrokinetic turgidity in neap and spring tides: its subsidence after devastation: its sterility in the circumpolar icecaps, arctic and antarctic: its climatic and commercial significance: its preponderance of 3 to 1 over the dry land of the globe: its indisputable hegemony extending in square leagues over all the region below the subequatorial tropic of Capricorn: the multisecular stability of its primeval basin: its luteofulvous bed: its capacity to dissolve and hold in solution all soluble substances including millions of tons of the most precious metals: its slow erosions of peninsulas and islands, its persistent formation of homothetic islands, peninsulas and downwardtending promontories: its alluvial deposits: its weight and volume and density: its imperturbability in lagoons and highland tarns: its gradation of colours in the torrid and temperate and frigid zones: its vehicular ramifications in continental lakecontained streams and confluent oceanflowing rivers with their tributaries and transoceanic currents, gulfstream, north and south equatorial courses: its violence in seaquakes, waterspouts, Artesian wells, eruptions, torrents, eddies, freshets, spates, groundswells, watersheds, waterpartings, geysers, cataracts, whirlpools, maelstroms, inundations, deluges, cloudbursts: its vast circumterrestrial ahorizontal curve: its secrecy in springs and latent humidity, revealed by rhabdomantic or hygrometric instruments and exemplified by the well by the hole in the wall at Ashtown gate, saturation of air, distillation of dew: the simplicity of its composition, two constituent parts of hydrogen with one constituent part of oxygen: its healing virtues: its buoyancy in the waters of the Dead Sea: its persevering penetrativeness in runnels, gullies, inadequate dams, leaks on shipboard: its properties for cleansing, quenching thirst and fire, nourishing vegetation: its infallibility as paradigm and paragon: its metamorphoses as vapour, mist, cloud, rain, sleet, snow, hail: its strength in rigid hydrants: its variety of forms in loughs and bays and gulfs and bights and guts and lagoons and atolls and archipelagos and sounds and fjords and minches and tidal estuaries and arms of sea: its solidity in glaciers, icebergs, icefloes: its docility in working hydraulic millwheels, turbines, dynamos, electric power stations, bleachworks, tanneries, scutchmills: its utility in canals, rivers, if navigable, floating and graving docks: its potentiality derivable from harnessed tides or watercourses falling from level to level: its submarine fauna and flora, numerically, if not literally, the inhabitants of the globe: its ubiquity as constituting 90 percent of the human body: the noxiousness of its effluvia in lacustrine marshes, pestilential fens, faded flowerwater, stagnant pools in the waning moon.

50它的普遍性，它的民主的平等性，以及保持着它自身求平的本质。用墨卡托投影法在地图上所标示出的浩淼的海洋；太平洋中巽他海沟那超过八千噚的不可测的深度；永不消停、后浪推前浪地冲刷着海岸线每一部位的波涛以及水面上的微粒子；水的单位粒子的独立性；海洋变幻莫测；根据液体静力学，风平浪静时它纹丝不动；根据液体动力学，小潮大潮时它便涨了起来。暴风雨后一片沉寂；北极圈与南极圈冰冠地带的不毛性以及对气候及贸易的影响；跟地球上的陆地相比占三对一优势；它在亚赤道带南回归线以南的整个区域延伸无数平方海里的绝对权威；其在原始海盆里数千万年以来所保持的稳定性；它那橙红色海床；它那把包括数百万吨贵金属在内的可溶解物质加以溶解，并使之保持在溶解状态的性能；它对半岛和有下陷趋势的岬角所产生的缓慢的浸蚀作用；其冲积层；其重量、容积与浓度；它在咸水湖、高山湖里的静谧；其色调因热带、温带和寒带而变为或浓或淡；与陆上的湖泊、溪流及支流汇合后注入海洋的河川，还有横跨大洋的潮流所构成的运输网。沿着赤道下面的水路自北向南的湾流；海震、水龙卷、自流井、喷泉、湍流、漩涡、河水暴涨、倾盆大雨、海啸、流域、分水岭、间歇泉、大瀑布、漩流、海漩、洪水、泛滥、暴雨等滥施淫威；环绕陆地的上层土壤那漫长的曲线；源泉的奥秘可用探矿杖来占卜或用湿度测定器来揭示；阿什汤大门的墙壁上的洞、空气的饱和与露水的蒸发能够证明那潜在的湿度；水的成分单纯，是氢二、氧一的化合物；水的疗效；水的死海里的浮力；它在小溪、涧谷、水坝的缝隙、船舷的裂口所显示的顽强的浸透性；它那清除污垢、解渴、灭火、滋养植物的性能；作为模范和典型，它的可靠性；它变化多端：雾、霭、云、雨、麦、雪、雹；并在坚固的消防龙头上发挥出压力；而且千姿百态：湖泊、湖岔、内海、海湾、海岬、环礁湖、环状珊瑚岛、多岛海、海峡、峡江、明奇、潮汐港湾、港湾；冰河、冰山、浮动冰原显示出它是何等坚硬；在运转水车、水轮机、发电机、发电厂、漂白作坊、鞣皮厂、打麻厂时，它又是那样驯顺；它在运河、可航行的河川、浮船坞和干船坞所起的作用；潮汐的动力化或利用水路的落差使它得以发挥潜力；海底那些成群的动物和植物虽然并非名副其实地栖息在地球上，论数目却占地球上生物的一大半；水无所不在，占人体的百分之九十；在沼泽地、闹瘟疫的湿地、馊了的花露水以及月亏期那淤积污浊的水塘子，水所散发的恶臭充满了毒气。

A method based on the orthogonal property between signal subspace and noise subspace is proposed for robust adaptive beamforming. The robustness would be achieved by projecting the signal steering vector and the null constrain steering vector on signal subspace followed by LCMVB.

针对此情况，基于信号子空间与噪声子空间的彼此正交特性，对存在误差的信号导向矢量和干扰导向矢量，同时向信号于空间投影，然后对投影后的导向约束采用LCMV准则进行自适应波束形成。

Finish to design the micro CNC, I have to investigate the adaptable parameters for cutting. This paper had calculated tool's radius, spindle's rotational speed, radial depth, and feed speed by the instantaneous cutting areas of the cutting forces model. To find out the instantaneous cutting areas by mathematica which can calculate the tangential, radial and axial component of cutting forces during cutting.

设计完微型工具机后，接著探讨最佳的切削参数，本论文采用瞬时投影面积的数学模型，且推导出利用刀具半径、主轴转速、径向切深、进给速度等参数来做为瞬时切削投影面积的函数，并使用软体mathematica算出瞬间面积大小，预测出切削过程里所产生的切线切削力、径向切削力和轴向切削力。

The housing (8) extends rearward of the rear projection screen (6) and has an opening (16) formed therein.

外壳(8)向后投影屏幕(6)之后延伸，并具有一个在其中形成的开口(16)。

Results The length between posterior superior iliac spine and greater trochanter of femur was (15.2±1.35) cm for man and (11.5±0.72) cm for woman; the length between posterior superior iliac spine and ischial tuberosity was (13.3±0.87) cm in man and (10.3±0.49) cm in woman; the length between greater trochanter of femur and ischial tuberosity was (8.3±0.83) cm in man and (5.5±0.61) cm in woman; the surface projection where the superior gluteal artery, superior gluteal veins and superior gluteal nerve permeate the suprapitiform foramen was below the point 0～6.8 mm between 2/5 superior and middle trunk from posterior superior iliac spine to greater trochanter of femur; the surface projection where the inferior gluteal artery, inferior gluteal veins and inferior gluteal nerve permeate the infrapiriform foramen was at the point between 2/5 inferior and middle trunk from posterior superior iliac spine to ischial tuberosity; the surface projection where sciatic nerve permeate the infrapiriform foramen was at the point between 3/5 lateral and middle trunk from ischial tuberosity to greater trochanter of femur.

结果臀三角各边的长度分别为：髂后上棘转子间距，男(15.2±1.35) cm，女(11.5±0.72) cm；髂后上棘结节间距，男(13.3±0.87) cm，女(10.3±0.49) cm；转子结节间距，男(8.3±0.83) cm，女(5.5±0.61) cm。臀上动脉、静脉、神经出入梨状肌上孔的体表投影在髂后上棘与大转子连线中、上2/5交界处向下0～6.8 mm内；臀下动脉、静脉、神经出入梨状肌下孔处的体表投影在髂后上棘与坐骨结节连线中、下2/5处；坐骨神经出梨状肌下孔处的体表投影在坐骨结节与大转子连线中外3/5处。

With this method the scattering waves of a truck model are studied in UHF band.

以复合激励方法为基础，并作为后续研究的起始，本文采用后向投影算法，对地表背景下的卡车进行成像仿真。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。