半有限的

In this paper, we summarize the foundations of Algebraic function fields, algebraic curves over finite fields and algebraic geometry codes, then we focus on the dimensions of codes on the quotient of the hermitian curves, by using the theory of weierstrass semigroup and the idea of Ho...

我们在系统地总结了代数函数域，有限域上的代数曲线和代数几何码的基本知识的基础上，利用Weierstrass子半群理论，使用Homma和Kim的方法，讨论了Hermite曲线商域上码的维数问题，得到的主要结果如下： 1。

Because the EPWE method is designed to derive easily the evanescent modes which can be used for the matching boundary conditions, we can get the transmittance for the semi-infinite photonic crystal. In this study, some interesting behaviors can be observed, for example, the transmittance is very sensitive to the surface we chose. The transmittance even can be almost 1 or 0 when the cutting planes of photonic crystal are different for the specific frequency. In this proposal I want to see the reason of the total reflection which seems to be conflicted with the existence of the propagation modes at that frequency and what will be happened when we consider the finite thickness case.

在EPWE 的方面，在这三年的时间里，我会尽量完成有限厚度的光子晶体的计算，因为以前主要算的是半无穷的光子晶体的计算，当中也看到了一些很有趣的行为，比方某些频率下，其穿透率与它的介面有很大的关系，因为，当光子晶体的切面不同，在特定频率下，其穿透率可以由几乎全穿透变成全反射，这里我想看看如果考虑厚度，到底会对系统有什麼影响。

In this paper, based on an optimum difference operator for spatial differential given by Holberg, an optimum difference method of modeling crosswell elastic wavefield is put forward, which adopts the staggered-grid technique and calculates the wavefield at different grid points. When the half length of optimum difference operator is taken as four to six points, the required number of grid points per wavelength equals to three, crosshole elastic wavefield numerical modeling can attain satisfied accuracy.

本文以Holberg提出的一种空间微分的最佳差分算子为基础，采用交错网格技术，提出了一种模拟井间弹性波场的最佳差分法，该方法能在大空间网格点上得到精确的波场值，当最佳差分算子的半长度取4～6个点，每个波长只采3个样点时，井间弹性波场的模拟就可以得到满意的精度，其计算速度比常规有限差分法至少快一个数量级。

But the volume fraction of particles in composite fabricated by prefabricate method was finite.

但是预制件法制备的复合材料的颗粒体积分数有限，无旋涡机械搅拌法的制备温度高，故这两种方法均不适合制备体积分数高（大于 20％）、颗粒尺寸小的复合材料而利用半固态机械搅拌法，能够将颗粒尺寸为3.5μm；体积分数为40％的SiC颗粒加入到金属Al中，但是当颗粒体积分数大于30％时，机械搅拌方式不能将颗粒均匀地分散在基体金属中。

This paper first analyses and summarizes the ststus quo and evolution trend of encryption, some common used cryptograph are introduced, including the algorithms used in symmetric cryptosystem and asymmetirc cryptosystem. We describe the theory of each algorithms and compare the elliptic curve cryptosystem with the other two asymmetric cryptosystems to show the advantages of this algorithm. Second, the principle of ECC is discussed, including the math foundation of ECC, basic conception of elliptic curves, constructiong idea of ECC, operation on the elliptic curve and so on. Third, the current attacks of ECC were analyzed deeply, and an algorithm based on limited prime number field was constructed. We analyzed its realizability in theory, and implement it by using certain function of MIRACL software package. Latter half in this paper, the implementation model of a simple elliptic curve encryption system which based on GF has been introduced. The paper also put a deep analysis on the algorithm of point addition and point multiplication.

本文首先对密码技术的发展现状及其发展趋势进行了分析和综述，详细的介绍了私钥密码系统和公钥密码系统的发展，说明各种算法的原理和优缺点，并给出了一些典型的密码体制的简要分析，重点将椭圆曲线算法与其它几种公钥密码算法比较，说明椭圆曲线算法的优势；其次，探讨了椭圆曲线密码体制的原理，包括椭圆曲线密码的数学基础、基本概念、椭圆曲线密码体制的构造思想等问题；第三作者对椭圆曲线的攻击现状作了详细的分析，针对所使用的大素数域F_p，设计了素数域上安全椭圆曲线产生的算法，从理论上做了可实施性分析，从软件上做了具体实现；在本文的后半部分，提出了一个简单的基于有限素数域上的椭圆曲线加密方按算实现模型，并对SECES中设计的点加和点乘运算进行了深入分析。

The so-called AT-algebras are inductive limits of finite direct sums of matrices over the extension algeras of circle algebra by K, where K is the C~*— algebra of all compact operators on a separable infinite dimensional Hilbert space.

若V_*与V_*同构，且保持单位元等价类；T与T仿射同胚，且同构映射与同胚映射相容，则存在E与E′的同构导出上述同构和同胚，所谓AT-代数即为圆代数通过κ的本质酉扩张的矩阵代数的有限直和的归纳极限，这里κ为可分的无限维复Hilbert空间上的紧算子全体，不变量中的V*为三变元Abel半群，T为迹态空间，[1]为单位元所在的Murray-von Neumann等价类，r_E为连接映射。

For a group G, and a subset S of G such that 5, the bi-Cayley graph BCay of G with respect to S is the bipartite graph with vertex set G {0,1} and edge set {{(g,0),(sg, 1)} In [1], the authors have discussed some semisymmetric cubic graphs.

对群G和G的子集S，关于S的双Cayley图Γ=BCay是一个二部图，满足：V=G×{0，1} E={{(g，0)，(sg，1)}|g∈G，s∈S}本文研究了有限非交换单群3度双Cayley图，在[1]中，已经讨论了关于A_n的3度半对称图的一些情况。

On the other hand, due to the special geometric shape of the side-chain polymers, at the corresponding bandgap edges of the infinite periodic chain, there exsit a pair of small transmittant peaks, which represents the residual periodicity in the chains.

当有限长度的具有随机支链的高聚物链连接到两个半无限长的金属导线上时，在严格扩展态处的透射峰的峰值有所下降，这是由高聚物和导线在界面处的位相失配引起的。

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。