导出代数

In recent years, derived categories and derived equivalences have been adapted extensively to a number of subjects beyond algebraic geometry, and have become one of the dominant subjects.

由Grothendieck-Verdier在上个世纪60年代提出的导出范畴的概念和建立的理论体系，标志着代数学发展的一个新的里程碑，它架设了代数与几何联系的一座桥梁。

Secondly, by applying inverse Fourier integral transform to the displacement, and uniting the constitutive and geometrical equations, the analytical expression of stress in Laplace domain were derived. Thirdly, by defining dislocation density functions, the Cauchy singular integral equations were obtained according to the boundary condition and interface connection conditions, and the problem was reduced to algebraic equations by Chebyshev orthogonal polynomial. Based the these, the unknown coefficient of the algebraic equations can be solved by Schmidt method. Finally, the time response of dynamic stress intensity factor and energy release rate are obtained by inverse Laplace transform.

首先，利用积分变换方法，推导出粘弹性层的控制方程组；其次，引入位错密度函数，并结合边界条件和界面连接条件，导出反映裂纹尖端奇异性的Cauchy型奇异积分方程组，然后，应用Chebyshev正交多项式化奇异积分方程组为代数方程组，并采用Schmidt方法对其数值求解，最后，经过Laplace逆变换，求得动态应力强度因子和能量释放率的时间响应。

The parametric speed of the curve is firstly approximated by the Bernstein polynomial, which takes the lengths of control point vectors of the direction curve of normal as Bézier coordinates.

其次 ，基于参数速度的 L egendre多项式逼近和插值区间端点的 Jacobi多项式逼近，导出了保持法矢平移方向的两种代数方式的等距有理逼近算法。

Similar to [KV2], for a Dynkin-algebra A, we prove that there is a bijection between the bi-aisles in Db and thestrictly full triangulated subcategories of Db which are closed under direct sum-mands.

运用[KV2]中的技巧，对Dynkin型k-代数A的模范畴的有界导出范畴Db，我们证明了其上的双aisles与其上的严格的且关于直和项封闭的三角满子范畴存在着一一对应的关系。

With regard to the section of coset in algebraic structure, a series of well-mastered concepts including equivalent relationship and division are applied, and typical examples are cited to introduce the conception of equivalent relationship-coset relationship defined through subgroup.

对于其中代数结构部分的陪集一节，应用已经熟知的等价关系和划分的概念，通过引例导出由子群定义的等价关系―陪集关系，进而得到群的划分―陪集，再研究陪集的性质。

From the point of algebra, ablock decomposition formula for coefficient matrix of discrete Hartley transform isgiven, from which a new fast DHT recursive algorithm is derived.

本文首先从代数角度出发，给出离散Hartley变换系数阵的一种块分解式，由此导出DHT的一种新的快速递归算法。

At present, frequency-wavenumber domain expression has been derived by Lie algebra integral and exponential mapping, and we need to research the method of transform from wavenumber domain to space domain.

目前，通过李代数积分和指数映射的研究，已经导出频率波数域表达式，需要研究波数域到空间域变换的实现方式。

After descibing the concepts, definitionsand operation approaches of quantum group and SLq(2) Lie algebra, the physicalmeaning of quantum group particles is explained in the present thesis. The gaugeinvariance in SLq(2) gauge field and its thermodynamics model is considered basedon the idea of q-deformation. The zero energy gap equation and q-deformed energygap equation are derived under the assumption of q-quantization and semi-classical q-quantization, then the zero-temperature energy gap A(0,q) and crititical temperature〓 can be calculated from the q-energy gap equation.

在介绍了量子群和SLq(2)李代数的基本概念，定义和运算方法后，文中进一步阐述了量子群粒子的物理意义；在q变形思想基础上，本文研究了SLq(2)规范场及其热力学模型中的规范不变性质，并在q量子化和半经典q量子化的假设下导出了零能隙方程和q变形能隙方程；然后从q能隙方程计算了与零温度能隙△(0，q)和临界温度〓。

By integral transformation of basic equations, the stress and displacement expressions with unknown coefficients of elastic and viscoelastic materials were obtained in Laplace domain respectively, and introducing dislocation density functions, the singular integral equations were got according to the boundary conditions and interface connection conditions, further adopting Gauss integration and Gauss-Jacobi integration formula, the problem was reduced to algebraic equations, then it can be solved with the method of collocation dots in Laplace domain. Finally, the time response of dynamic stress intensity factor was calculated with the inverse Laplace integral transformation.

采用积分变换方法，得到Laplace域内弹性和粘弹性材料的应力和位移的含未知系数的表达式；引入位错密度函数，并通过边界条件和界面连接条件，导出反映裂纹尖端奇异性的奇异积分方程组，采用Gauss积分，并运用Gauss-Jacobi求积公式化奇异积分方程组为代数方程组，利用配点法进行求解；最后经过Laplace逆变换，求得动态应力强度因子的时间响应。

An inhomogeneous Benjamin-Davis-Ono-Burgers equation including topographic forcing and turbulent dissipation is derived in terms of the quasi-geostrophic vorticity equation, an approximate analytic solution of the BDO-Burgers equation with a small dissipation is obtained, the time variations of mass and energy of the algebraic solitary waves are discussed, and finally, the forced BDO-Burgers equation is integrated numerically and the numerical solutions are given for a given basic flow with a weak shear and a localized topographic forcing.

利用包括地形外源和湍流耗散的准地转涡度方程导出了包含强迫项和湍流耗散项的非齐次强迫BDO-Burgers方程，求出了小耗散存在情况下BDO-Burgers方程的近似解析解，讨论了代数孤立波的质量和能量的守恒关系，最后，对给定的弱切变基本气流和局地地形强迫，数值积分强迫BDO-Burgers方程，求得了不同参数下的数值解。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。