小的环

The controller makes the closed-loop systems internally stable and minimizes the H2 norm of the transfer matrix Tzw from w to z. Two Riccati formulae based on 8 operator is deduced. The H2 problems for continuous time systems, Z operator models and 8 operator models are investigated respectively.The guaranteed cost control problem of robust stabilization and robust performance for uncertain systems which is described by 8 operator is discussed in this paper.

采用Riccati方程处理方法讨论了基于Delta算子描述下的离散系统存在输出反馈控制器的问题，得到了两个基于Delta算子的Riccati方程，设计了Delta域的输出反馈控制器，使得闭环系统内稳定，且满足从w到z的传递矩阵T_的H_2范数最小，设计了基于Delta算子描述下的离散系统的最优控制器，并与S域和Z域的H_2控制器进行了比较。

A predator model with refuge and toxicity is studied. By constructing a suitable Dulac function, it is shown that there is no limit cycle in the first quadrant, thus the globally stability of the equilibrium is proved. Further more, the paper analyzes the influence of refuge, toxicity and harvesting. It is amazing that ① if the death rate of predator is big or the harvesting effort is big, the existence of the predator is unrelated with refuge; if the death rate of predator and the harvesting effort are small, and the refuge is small enough, the population of both species is increased as the increase of refuge;② if d2=0, the increase of d1 has no influence on the prey population, while the population of predator is decreased.

研究一类有避难所、毒素作用和外界捕获影响的捕食系统，通过构造恰当的Dulac函数，证明系统在第一象限没有极限环，从而证明了平衡点的全局稳定性；分析了避难所、毒素、捕获作用对该系统最终种群数量的影响，发现：①当捕食者的死亡率大或其被捕获得多时，两种群的绝灭与避难所的存在无关；当捕食者的死亡率小、被捕获得多且避难所足够小时，随着食饵避难所的增加，捕食者种群数量也随之增加；②当毒素d2=0时，毒素d1的增加对食饵种群最终数量没有影响，而使捕食者种群数量下降。

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。

The conclusions can be drawn through numerical simulation: The hydrate-forming region becomes small with increasing circulation rate and inhibiter concentration, and it is possible to make the hydrate-forming region away from sea floor by increasing circulation rate and inhibiter concentration, thus preventing blowout preventer lines from hydrate plugging; the decrease in gas volume fraction in the annulus due to hydrate formation reduces pit gain, which can delay the detection of well kick; the possibility of hydrate presence at a relatively low gas production rate is much greater than that at a relatively higher production rate; the bottom hole pressure is affected little by hydrate phase transition, and it is allowable not to consider hydrate phase transition when the bottom hole pressure is calculated; shut-in casing pressure cann't truly reflect gas kick due to hydrate formation and the situation is getting worse with time

模拟计算结果表明：溢流期间，天然气水合物的生成区域会随着循环流量的增大或抑制剂浓度的提高而减小，可通过增大流量和抑制剂浓度使水合物的生成区域脱离海底，减小防喷器管线被堵塞的危险；水合物的生成使环空中气体体积分数降低，泥浆池增量减小，给溢流检测带来延迟；当检测到有气侵发生时，水合物藏分解速率比较小时，井筒中生成水合物的可能性要比分解速率大的情况下更为严重；水合物相变对井底压力的影响较小，在工程中计算井底压力时可以忽略；由于天然气水合物的生成使得关井套压值不能真实反应气侵情况，而且随着时间的增加情况会更加严重。

Their adsorption rate on the molecular sieve catalysts surface and the stability of their carbonium ions were then obtained based on the molecular simulation on these molecules from their dipole moment, 2-dimensional electrostatic potential energy contours and 3-dimensional electrostatic potential energy isosurface.

采用半经验的AM1量子化学计算方法和静态理论，分别考察了噻吩、 3 甲基噻吩和 2 ，5 二甲基噻吩分子结构特性的不同，从偶极矩、各自垂直于芳香环平面的二维电势能分布曲线和整个分子周围三维电势能分布情况等方面分析了它们在分子筛催化剂表面吸附速度的快慢和生成正碳离子稳定性的高低，进一步比较了噻吩及其衍生物所生成的正碳离子进一步反应的能量变化，从而可判断噻吩及其衍生物裂化脱硫速度的快慢，噻吩及其衍生物裂化脱硫的速度由大到小分别为：2 ，5 二甲基噻吩、 3 甲基噻吩、噻吩。

Based on analysis of the current state of the flow pattern modeling abroad and at home, explains the meaning of the mathematical simulation of the flows in the valve.(2) Comparing flow simulation data of jet pump with its experimental one, the feasibility and reliability of FLUENT used for flow simulation are proved.(3) Based on the characteristic of valves, the fluid field analysis of specific ring-spray type flow-adjustable is finished. The valve structure is optimized to meet the need, which makes it have such advantages:(1)smaller vortex area and faintish vortex intensity, so the vibration of vortex is controlled effectively;(2)the pressure is distributed more equality, the transition area is larger.

论文的主要内容包括：(1)简述了阀门研究的现状与发展，在分析与总结国内外流体流动模拟研究的基础上，探讨开展阀门内水流运动数值模拟的意义；(2)对特定型号的射流泵进行了内部流场的数值模拟研究，并与实验数据相比较，验证了应用Fluent进行数值模拟的可行性和可靠性；(3)针对调流阀的特点，对特大口径环喷式流量调节阀进行流场计算，其设计指导思想如下： 1、控制旋涡，减小旋涡区，减小涡的强度； 2、控制压力分布，使阀体受力更均匀，改善局部应力状态，提高阀门使用的安全性； 3、最小绝对压力高于水的汽化压力，不产生汽蚀。

WD40 domain, found in a number of eukaryotic proteins that cover a wide variety of functions including adaptor/regulatory modules in signal transduction, pre-mRNA processing and cytoskeleton assembly; typically contains a GH dipeptide 11-24 residues from its N-terminus and the WD dipeptide at its C-terminus and is 40 residues long, hence the name WD40; between GH and WD lies a conserved core; serves as a stable propeller-like platform to which proteins can bind either stably or reversibly; forms a propeller-like structure with several blades where each blade is composed of a four-stranded anti-parallel b-sheet; instances with few detectable copies are hypothesized to form larger structures by dimerization; each WD40 sequence repeat forms the first three strands of one blade and the last strand in the next blade; the last C-terminal WD40 repeat completes the blade structure of the first WD40 repeat to create the closed ring propeller-structure; residues on the top and bottom surface of the propeller are proposed to coordinate interactions with other proteins and/or small ligands; 7 copies of the repeat are present in this alignment.

WD40域，在真核蛋白质的数量发现，涵盖了包括各种功能适配器/信号转导，mRNA前体细胞骨架组装加工和管理模式；通常包含一个从11月24日生长激素肽的N残留端和西部数据肽在其C端和40残留长，因而得名WD40；介于生长激素和WD一个保守的核心，作为一个稳定的螺旋桨式平台，可以绑定的蛋白可以稳定或可逆，形成了一个螺旋桨式与每个刀片是一个四叶片结构组成若干链反平行的β-片；与数份检测实例假设，形成了聚大结构，每个WD40重复序列形成了前三个一个刀片和绞线的最后在未来的刀片链，最后C -末端WD40重复完成了第一WD40重复叶片结构，创造螺旋桨的封闭环结构，对螺旋桨顶部和底部表面残留的建议，配合和其他蛋白质的相互作用/或小配体； 7重复副本，目前这条路。

WD40 domain, found in a number of eukaryotic proteins that cover a wide variety of functions including adaptor/regulatory modules in signal transduction, pre-mRNA processing and cytoskeleton assembly; typically contains a GH dipeptide 11-24 residues from its N-terminus and the WD dipeptide at its C-terminus and is 40 residues long, hence the name WD40; between GH and WD lies a conserved core; serves as a stable propeller-like platform to which proteins can bind either stably or reversibly; forms a propeller-like structure with several blades where each blade is composed of a four-stranded anti-parallel b-sheet; instances with few detectable copies are hypothesized to form larger structures by dimerization; each WD40 sequence repeat forms the first three strands of one blade and the last strand in the next blade; the last C-terminal WD40 repeat completes the blade structure of the first WD40 repeat to create the closed ring propeller-structure; residues on the top and bottom surface of the propeller are proposed to coordinate interactions with other proteins and/or small ligands; 7 copies of the repeat are present in this alignment.

WD40域，在真核蛋白质的数量发现，涵盖了包括各种功能适配器/信号转导，mRNA前体细胞骨架组装加工和管理模式；通常包含一个从11月24日生长激素肽的N残留端和西部数据肽在其C端和40残留长，因此得名WD40；之间的生长激素和WD是一个保守的核心，作为一个稳定的螺旋桨式平台，可以绑定的蛋白可以稳定或可逆性；形式与每个刀片是一个四叶片组成的几个类似结构的螺旋桨，搁浅反平行β-负债表；很少检测副本实例假设，形成了聚大结构，每个WD40重复序列形成了前三个链的一个刀片，并在未来的刀片上链，最后C -末端WD40重复完成了第一WD40重复叶片结构，创造螺旋桨的封闭环结构，对螺旋桨顶部和底部表面残留物，则建议协调与其他蛋白质和/或小配体； 7重复副本存在于相互作用这条路。

WD40 domain, found in a number of eukaryotic proteins that cover a wide variety of functions including adaptor/regulatory modules in signal transduction, pre-mRNA processing and cytoskeleton assembly; typically contains a GH dipeptide 11-24 residues from its N-terminus and the WD dipeptide at its C-terminus and is 40 residues long, hence the name WD40; between GH and WD lies a conserved core; serves as a stable propeller-like platform to which proteins can bind either stably or reversibly; forms a propeller-like structure with several blades where each blade is composed of a four-stranded anti-parallel b-sheet; instances with few detectable copies are hypothesized to form larger structures by dimerization; each WD40 sequence repeat forms the first three strands of one blade and the last strand in the next blade; the last C-terminal WD40 repeat completes the blade structure of the first WD40 repeat to create the closed ring propeller-structure; residues on the top and bottom surface of the propeller are propos

WD40域，在真核蛋白质的数量发现，涵盖了包括各种功能适配器/信号转导，mRNA前体细胞骨架组装加工和管理模式；通常包含一个从11月24日生长激素肽的N残留端和西部数据肽在其C端和40残留长，因而得名WD40；介于生长激素和WD一个保守的核心，作为一个稳定的螺旋桨式平台，可以绑定的蛋白可以稳定或可逆，形成了一个螺旋桨式与每个刀片是一个四叶片结构组成若干链反平行的β-片；与数份检测实例假设，形成了聚大结构，每个WD40重复序列形成了前三个一个刀片和绞线的最后在未来的刀片链，最后C -末端WD40重复完成了第一WD40重复叶片结构，创造螺旋桨的封闭环结构，对螺旋桨顶部和底部表面残留的建议，配合和其他蛋白质的相互作用/或小配体； 7重复副本，目前这条路。

However, this is mostly true for signals we receive directly, like noise sources, and not so much for signals from broadcast stations coming to us through skywave propagation. I aim the antenna for minimum noise pickup, which results in the best signal to noise ratio. In some situations it is quite possible to fully tune out a noise source such as a TV or computer monitor.

喜欢听干扰台的有福了，VOA和干扰台的信号不会是一个方向来的，把环对准VOA信号最强的方向，那么在另外方向的干扰信号就会衰减，VOA来的斗争指示你会听得更清），我更感兴趣的是最小噪声拾取，这会带来会好的信噪比，在一些情况下，很有可能将电视或电脑带来的噪声剔出出去。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。