律

We cannot always have associative law for operations, for instance, we did not have this law for mixed addition and multiplication,neither for subtraction, 2+3 2+1≠(2+3)(2+1)=5 3,（2-3）- 2≠2-（3-2）,this is why we have to set the rule in operations that "doing inside bracket at first and out side afterwards, doing multiplication and dividing first and addition and subtraction afterwards".

注意运算的结合律并不是永远对的，比如加法和乘法的混合运算就没有结合律，减法也没有，2+3 2+1≠5 3，（2-3）- 2≠2-（3-2），因此我们运算中总是规定先括号内再括号外，先加减后乘除。

Firstly, using strategy of introducing associated auxiliary equation to a givenpartial differential equation without admitting Lagrangian, we make the extendedequations possess a variational principle. Based on this, the concepts of extendedconservation law and extended symmetry to given partial differential equationare put forwarded.

首先，我们给出了引入伴随方程扩充原方程的策略，使给定偏微分方程的扩充方程组具有对应泛函，即称为Lagrange系统的方法，以此为基础提出了作为偏微分方程传统守恒律和对称概念的一种推广—偏微分方程扩充对称和扩充守恒律的概念；其次，先给出以得到的Lagrange系统为基础，利用N？

This paper describes the basic principle of velocity pursuit guidance law and body pursuit guidance law of trajectory correction projectiles , researches the terminal correction trajectory and miss distance under pursuit guidance laws by 6—DOF trajectory simulation program, researches the orbit of laser detector ray axis and ground projection area of laser detector spatial viewpoint.

文中对速度追踪制导律和弹体追踪制导律的工作原理进行了研究，利用六自由度弹道仿真程序对弹道修正弹两种追踪方式下的末段修正弹道和脱靶量进行了对比计算，研究了两种追踪方式下激光探测器光轴的轨迹及激光探测器空间视场在地面投影区域的变化；弹体追踪方式命中精度虽然较低，但由于工程实现简单、成本低，仍有其工程使用价值。

The divine origin of the written law is emphasized by a bas-relief in which the king is depicted receiving the code from the sun god, Shamash.

书写律法的神圣来源被一块浅浮雕所强调，里面刻着的国王被描述为从太阳神沙玛什那里获取律法。

When fitness satisfies the bimodal distribution, the connectivity distribution of the network satisfies a generalized power-law form.

当Fitness服从一个双模分布时，网络的度分布是一个广义的幂律形式；当Fitness服从均匀分布时，网络的度分布是一个带有对数修正的广义的幂律形式。

Bordered matrix has very wide applications in the matrix theory, many specialists and scholars had studied bordered matrices before.

本节在P-SVD中通过构造特殊的非奇异矩阵，详尽地揭示了两个矩阵乘积{1，3}-和{1，4}-逆的结构，从而最终解决了两个矩阵乘积{1，3}-和{1，4}-逆的反序律，并得到了两个矩阵乘积伪逆反序律的一个新的等价性条件。

A new efficient method of numerical iteration solution to the boundary value problem was put forward.

结合航天飞机和飞马火箭的制导律，进行了制导技术的开发，提出了一种新的基于该控制律的火箭真空段运动的多变量边值问题的有效数值迭代解法。

This problem, which was certainly known to the ancients, became especially acute in the seventeenth century with the invention of celestial mechanics, which first gave philosophers a certain picture of a way the world might be: it might be a world whose future states were entirely determined by the past and the laws of nature (of which Newton's laws of motion and law of universal gravitation served as paradigms).

这个从很早就被知道的问题，在十七世纪之后变得尖锐起来，因为引力力学第一次给予了哲学家一个明确的世界图景：可能世界的未来事态完全可以被过去和自然律（Newton的运动律和万有引力定律是范例）所决定。

According to analyzing on the consistent degree of addition modulo 2∧n with XOR addition for commutative law, the computation formulas of the probability distribution of the noise function and the square sum of the probability values were presented, which is applied on the distinguishing attack on Py. The data complexity of our attack is about 2019∧（-1）times of the data complexity of the distinguishing attack on Py proposed by Sekar et al..

通过对模2∧n加与模2加相对于交换律的相容程度的分析，给出了模2n加与模2加相对于交换律所产生的噪声函数的概率分布及其取值平方和的计算公式，并利用此结果提出了一种对Estream候选算法Py的新的区分攻击方法，该方法所需的数据复杂性约为Sekar等提出的区分攻击所需数据复杂性的2019∧（-1）。

Clearly, the sum of games is a commutative and associative operation, as is the nim sum operation.

无疑，游戏的求和是满足交换律和结合律的运算，nim和运算也是。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。