查询词典 constant field
- 与 constant field 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The construction of the generators is of drip-proof salient pole rotating field self excitation constant voltage type.
建造该发电机是滴灌防爆,凸极旋转场自我激励和不断电压型。
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A lot of people like to do one job in their lives. They think people who change their jobs frequently are feckless. They believe that the only way to success is to stick to one job, for constant practice in a professional field helps make an expert.
许多人喜欢一生中做一件工作,他们认为经常换工作的人软弱无能,他们相信成功的唯一途径就是坚持一项工作,因为在一个专业领域里不断的实践有助于专家的形成。
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My View on Job-Hopping A lot of people like to do one job in their lives. They think people who change their jobs frequently are feckless. They believe that the only way to success is to stick to one job, for constant practice in a professional field helps make an expert.
我对"跳槽"现象的看法许多人喜欢一生中做一件工作,他们认为经常换工作的人软弱无能,他们相信成功的唯一途径就是坚持一项工作,因为在一个专业领域里不断的实践有助于专家的形成。
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It analysed the principle of Reed-Solomon encode, the design of basic unit circuit, including Galois field adder and multiplier, and addressed the application method of parallel multiplier with constant coefficients under the natural base.
分析了RS码的编码原理,基本单元电路设计,包括有限域加法器和乘法器,并着重阐述了自然基下常系数并行来法器的实现方法。
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The method includes steps: each point in sequence x with length L, i=0, 1, 2,apostrophe L-1 is served as a independent variable of k order polynomial; changing coefficient of polynomial to generate multiple sequence f with length L, where k is nonnegative integer; operation in polynomial is carried out in Galois Field GF, where Q=pm, p as a prime number, and m as nonnegative integer; assigning generated sequences to multiple sectors to set of create biased sequences for each sector; it is different in constant terms of polynomial, and identical to other coefficients of coefficients corresponding to sequence assigned to same sector; creating corresponding time - frequency pattern unit from biased sequences of the sector; repeating TFP unit with equal interval in frequency domain so as to obtain integrated TFP.
本发明涉及一种时频资源的分配方法,所述方法包括:把一个长度为L的序列{x,i=0,1,2,…L-1}中的每一点作为一个k次多项式的自变量,改变多项式的系数生成多个长度为L的序列{f},其中k是非负整数,多项式中的运算在伽罗华域GF中进行,其中Q=p m ,p是一个素数,m是非负整数;把生成的序列分配给多个小区,生成各小区的偏置序列集合,其中分配给同一个小区的序列所对应的生成多项式的常数项不同,其他项的系数都相同;由所述小区的偏置序列生成对应的时频图案单元,将时频图案单元经过频域等间隔重复,得到完整的时频图案。
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A quick and correct forecast of tidal current when oil spill occurs is a key step in the forecast of oil spill. Based on the harmonic constant of tidal component of M2, S2, O1 and K1 in Lingshan Island, Laoshantou and Chaolian Island, and by using harmonic method, the thesis first conducts a current forecast in a single point, and then builds up a current field forecast in Jiaozhou Bay and its adjacent seas. The computed results match well with the actual situation. The method reduces greatly the time of real time current forecast by not using numerical stimulation, so it fit to the two requirements of quickness and correctness in oil spill forecast system.
迅速准确地预测出溢油发生时的潮流情况是溢油环境预测的根本保证,因此文中根据灵山岛、崂山头和朝连岛三处M2、S2,、O1和K1四个主要分潮的调和常数资料,采用调和的方法进行单点的潮流预报,进而建立了胶州湾及邻近海域的预报潮流场;该方法的潮流预报结果与实际情况吻合良好,且因避开了数值计算过程而大大减少了流场实时预报的机时,符合溢油应急预报系统所要求的准确与快速。
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ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.
本论文针对车载异步电机在矢量控制器所遇到的问题:定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案:分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算,分析出对于电流型逆变器在采用定子磁场定向时,其性能同时具有矢量控制和直接转矩控制两者的优势,并对电压型逆变器在转子磁场定向下的模型进行了仿真研究;建立异步电机非线性模型,推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程,并做出了仿真结果,建立异步电机在非线性模型下的矢量控制调节器的PI参数设计,在实际应用中,若忽略电机电感的动态变化,可以根据当前的磁路饱和状态而在线修正电感参数,从而将非线性方程线性化,降低控制器的复杂度;考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出,本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题;推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通,用于实现高性能的矢量控制算法,并给出了仿真结果;推导出了电动汽车恒转矩给定的闭环回馈制动系统,实现了电动控制模型和制动模型的统一,而且结合铅酸电池最大充电电流的要求,为制动转矩在线给定建立了数学模型;设计了基于双DSP系统的高性能矢量控制器软硬件框图,并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。
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With the rapid development of economic integration and constant improvement of degree of openness in the most of countries, intercourse of the trade and financial field becomes more and more frequent. Under this kind of background, economic fluctuation is easy to take place because of external shocks through foreign trade, international capital flow and other channels. So, the research of economic cycle can not be taken only in closed environment. Focusing on the open e conomy, the discussion of influence on the economic cycle fluctuation from external shocks have rather important significance.
随着全球经济一体化的迅猛发展,各国经济开放程度不断提高,各国间贸易与金融领域的交往也日趋频繁,在这种背景下,通过对外贸易、国际资本流动等渠道本国的经济将会受到外来冲击的影响而发生波动,因此,对经济周期的研究不能仅停留在封闭条件下,着眼于开放经济的背景,探讨外来冲击对一国经济周期波动的影响具有相当重要的意义。
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With the angular velocity determined, I used Einstein's field equations and Kepler's laws to place an upper bound on the magnitude of the cosmological constant, which describes the curvature of space and the rate of the universe's expansion.In addition to learning science, I recently lectured physics classes on special relativity at the request of my physics teacher.
在校参加入党学习以来,我以一名党员的标准来严格要求自己,在思想上我积极要求进步,树立了良好的人生观和道德观;永远保持与时俱进,认真学习党的工作路线,正确贯彻党的方针政策,时刻关注着党和国家的发展形势,以及国内外的局势变化。
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The molecular charge distribution of the reactivator is affect the reactivating efficacy directly. Moreover its association with hydroximic acid dissociation constant pAa closely, and it will have a great impact on reactivating ability indirectly.(3) There is likely to exist front molecular interaction between Cholinesterase Reactivators and OPC-inhibited AChE, the action sites mainly lie on the aromatic ring, the substitute R and the hydroixic acid group. They act on the aromatic residues of AChE by Π-Π conjugation .(4) The reached results by Comparative Molecular Field Analysis is useful to design new higher efficacy derivatives for 1, 2, 4-oxadiazole class nonquaternary Cholinesterase Reactivators.
2复能剂分子的电荷分布直接影响复活活性,同时对肟酸解离常数pKa具有重要影响,间接影响复活能力;(3)复能剂与磷酰化酶可能存在前线轨道作用,作用部位可能主要在芳香环及其取代基R和肟基上,与AchE的芳香族残基发生л-л电子作用;(4)通过比较分子力场法研究可以指导1,2,4-oxadiazole类非季铵肟胆碱酯酶重活化剂新化合物的合成,可能得到活性更高的复能剂。
- 推荐网络例句
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The split between the two groups can hardly be papered over.
这两个团体间的分歧难以掩饰。
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This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.
这种做法不仅鼓励了更多的反应,而且减少跟风的可能性。
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The new PS20 solar power tower collected sunlight through mirrors known as "heliostats" to produce steam that is converted into electricity by a turbine in Sanlucar la Mayor, Spain, Wednesday.
聚光:照片上是建在西班牙桑路卡拉马尤城的一座新型PS20塔式太阳能电站。被称为&日光反射装置&的镜子将太阳光反射到主塔,然后用聚集的热量产生蒸汽进而通过涡轮机转化为电力