定向

Results The results of this stu dy theoretically proved that it is possible to target the deep brain structures when the stereotactic headframe was at any angle with the AC-PC line during the processes of the neurosurgery.

结果 从理论上证明，任意角度按装定向仪框架求脑深部结构的定向仪框架空间坐标是可行的，新方法较常规方法更接近金标准，并具有统计学意义。

To determine whether HPCs actually harbor the virus in infected people, Collins's team worked with a hematologist who removed HPCs from the bone marrow of 15 HIV-infected volunteers.

为了论证在感染人群中定向造血细胞是否在庇佑病毒，科林斯小组求助一位血液学家，他将15名感染HIV的志愿者骨髓里提取出定向造血细胞。

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。

Theorem Let M be a orientable or non-orientable closed surface, and f a C°-flow whose every singular point is isolated. Then f has POTP if and only if the following three conditions hold

定理 设M是任一个可定向或不可定向的闭曲面，f是M上任一个奇点均孤点的C〓-流，则f具有伪轨跟踪性质的充分必要条件是

After studying the theory of combined signal processing with acoustic pressure and particle velocity, a method of direction estimation underwater, which is based on intensity measurement using an acoustic vector sensor, is presented. In the low frequency field with kinds of line-spectra, azimuth angle estimation is achieved based on the probability density statistics and bar graph approach. It can preferably resolve the problem of left/right bearing resolution and estimate the direction of space.

为了对水下目标进行定位，基于声压与振速联合信号处理的理论，研究了复声强法对水下目标信号的定向技术，并使用概率统计和直方图的理论对目标的方位角和俯仰角值进行了估计，在线谱分量存在的低频段对估计角度进行了概率统计，较好地解决了左右舷的分辨问题，实现目标的全空间无模糊定向。

Article 30 Securities companies and asset custodians shall ensure that a client can at such time and in such manner as is agreed upon in a target asset management contract make inquiries about, among other relevant information, the portfolio status, changes in net value, transaction records of asset in his or its target asset management account

第三十条证券公司、资产托管机构应当保证客户能够按照定向资产管理合同约定的时间和方式，查询客户定向资产管理账户内资产的配置状况、净值变动、交易记录等相关信息。

Polytetra-fluoro-ethylene thin membrane,pass through cut tie by poly-4 fluorous second fluidized resinde,after sinter cut but succeed,direct membrane transfusives membrane transfusive membrane mangler direct but succeed again,It has undeniable electrical equipment insulate behaviopural,non-ageing and extensive use temperature lint.

聚四氟乙烯薄膜，车削带由聚四氟乙烯悬浮树脂经模压，烧结后车削而成。定向膜将车削膜再经压延机定向而成，它具有优良的电器绝缘性能，不老化及广阔的使用温度范围。

Mottles in leopard limestone have undergone rotational deformation and have certain preferred orientation,while the marly component shows distinct fea- tures of ductile deformation;it is r...

在露头尺度上，豹皮灰岩中的豹斑发生了明显的旋转变形并具有一定的定向性，而泥灰质成分则具有清晰的韧性变形特征，为较典型的碳酸盐糜棱岩；在微观尺度上，构成豹斑的白云石矿物未发生韧性变形，而泥灰质成分中的方解石具有明显的细粒化、拉长和定向。

Under the guidance of my teacher, a new model on unidirectional motion of molecular motor is put forward, in which the interaction between two heads is taken into account for the first time.

本文首次提出了双头相互作用的分子马达定向运动机制的模型，尝试了物理上研究分子马达定向运动机制的新方法。

In directional radar the directional characteristic is affected by nonideal sum and difference performance caused by small mismatch of microwave bridge port.

在定向雷达中，微波和差器的不理想性，对单脉冲雷达定向特性构成了一定的影响，这种不理想性主要由组成和差器的微波桥各端口的小失配形成。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

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。