阶数

For a general parametric curve/surface, we usually cannot compute its exact implicit form. Even though its exact implicit form can be computed, the curve/surface implicitization involves relatively complicated computation and the degree is higher. Moreover, it may have unexpected components and self-intersections. All these unsatisfied properties limit the applications of the exact implicitization. So finding curve/surface approximate implicitization has become a practical problem. In this paper, we present an algorithm to solve the approximate implicitization of a given parametric curve by using a quadratic algebraic spline curve.

由于精确隐式化过程不一定可以实现，即使可以实现隐式曲线曲面的阶数高计算复杂，并且具有不希望的自交点和奇异分支，从而限制了隐式化的运用，所以寻求参数曲线曲面的近似隐式化问题成为很实际又重要的问题，提出利用二次代数样条曲线来实现一般平面参数曲线近似隐式化的一种算法。

Single loop instantaneous voltage feedback control and multiple loop feedback control, which can be realized by digital method or analogue method, are normal control strategies of inverter. The controller's performance of a same control strategy designed by different designers is different This paper makes out uniform analysis and design theory of inverter control strategies with pole-assignment technique of state-space theory for the first time. It is firstly proposed that controller parameters being equal to control system orders is the base of realizing high performance inverter. Design and performance comparability of various controllers is presented with uniform pole-assignment method.

本文首次采用状态空间理论的极点配置技术，对逆变电源的几种控制策略进行了统一的分析和设计，首次提出控制器控制参数与控制系统阶数相等是高性能逆变器控制实现的基础，并通过极点配置这种统一的设计方法对各种控制器进行了设计和性能比较，分析了要考虑的一些非理想因素的影响。

Using analytic continuation in the coupling constant method within the framework of the self-consistent relativistic mean filed theory, we study the energies and the widths of the resonant states in ~(16)O nuclei, and the influences of the coupling constant interval and the Pade approximant order are analyzed.

考察了~(16)O的中子共振态能级，并且详细研究了耦合常数右端点对应能量的变化和Padé多项式的阶数对能量和宽度的影响。结果表明：适当选取耦合常数取值区间可以得到既收敛又稳定的结果。

The theory and approach are introduced, and the general expression containing arbitrary parameter is obtained for the feedback gain matrix. This method changes the problem of multi-input system to several problems of single-input. The number is the cycle index of system matrix. Compare with some known results, this method put forward that the least number of unknown entries of the feedback gain matrix is the order of the system matrix.

汽配置问题，得到了反馈增益矩阵的一般表达式，此表达式中含有任意参数，此方法将多输入线性系统极点配置问题转化为个数为系统矩阵循环指数的单输入系统的极点配置问题，进而推导出确定一个反馈增益矩阵的最少元素个数即为系统的阶数。

It is shown that the far-field divergence angle of nonparaxial rotationally LG beams approaches to an asymptotic value of 63.435° as the initial waist-width to wavelength ratio w0/λ approaches zero,which is independent of the order.

计算结果表明，当初始束腰宽度和波长之比w0／λ趋于0时，对任意非傍轴旋转对称LG光束，远场发散角趋于渐近值63.435°，与阶数无关。

It is found that as w0/λ(waist width-to-wavelength ratio)→0, the far-field divergence angle approaches an asymptotic value of θmax=63.435°,indenpent of the beam order.

研究表明，当w0/λ→0时，远场发散角趋于渐近值θmax=63.435°，与阶数无关。

The flow diagram and design steps are shown. An example of 3-cascaded, 5-order, 0.8 nm spacing filter is given out. The de- rived response is consistent with that of the ideal filter.

给出了PSO方案的设计流程及具体步骤，并设计了级联数为3、阶数为5和信道间隔为0.8nm的梳状滤波器，其输出响应与理论滤波器一致。

Therefore,a fast algorithm of NMF is presented.By some algebra formulation,the matrix to be factorized is changed into a low-dimension matrix which is a diagonal matrix whose dimension is related to the number of samples.Moreover the feature extraction for one sample only needs to calculate the inner product.

该算法通过代数变换，把对原高维矩阵的非负分解转换成非负的低维矩阵的非负分解，其求解过程只需要对一个阶数等于样本数的对角矩阵进行非负矩阵分解，同时提取某样本特征时只需要计算该样本与所有训练样本的内积。

However,there have been no papers which have investigated Minkowski and Minkowski slant helices and Minkowski conical geodesic curves so far as.In this paper,our major study is to give the definition of Minkowski general helix and Minkowski slant helices and Minkowski conical geodesic curves in indicators 1 in pseudo-Euclidean three-space (that is, three-dimensional Minkowski space), and study the definition of equivalence Minkowski general helix, By considering geometric invariants of these space curves, we can estimate the order of contact with those special curves for general space curves.

本篇文章主要研究在指标数为1的3维伪欧氏空间(即三维Minkowski空间)中，我们给出Minkowski一般螺线、Minkowski斜螺线和Minkowski锥面测地线的定义，研究Minkowski一般螺线的等价定义，给出Minkowski斜螺线和Minkowski锥面测地线作为三维Minkowski空间中的特殊曲线所特有的性质，并通过考虑三维Minkowski空间曲线的几何不变量，估计Minkowski斜螺线和Minkowski锥面测地线这两种特殊曲线和一般Minkowski空间曲线切触的阶数。

The focus of Fresnel zone lens is related to both the radius and the number of loops, however is independent to its phase grades.

在环带相位深度P为2p 时，菲涅耳波带透镜的焦距与其半径和环带数有关，而与相位阶数L无关。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。