双射

According to the boundary relations of the electromagnetic field, and based on the phenomena of double refraction and double reflection in crystals, the reflectivity and transmissivity are deduced at boundary when an extraordinary beam is incident from an isotropic medium upon a crystal or from a crystal to an isotropic medium with optical ax.

为分析非常偏振光在晶体表面的能量损耗，给出一种求解反射率和透射率的方法，即根据电磁场的边值关系以及晶体的双折射和双反射现象，求解晶体光轴在入射面内时，非常偏振光从各向同性介质入射到晶体和从晶体出射到各向同性介质两种情况的反射率和透射率的方法，并给出反射率和透射率的解析解，同时得到对于晶体光轴在入射面内的情况，光轴的取向对非常偏振光反射率的大小几乎没有影响，但对产生全反射的临界角θc影响较大的结论。

In judging of the radix of an indefinite set, an one-one mapping between it and a known radix of indefinite set must be found out.

由于在判断一个无限集合的基数时，必须找出它与另一个已知基数的无限集合之间的一个双射函数。

A Study on Fraunhofer Double-Slit Diffraction by Applying Simulation Technology;2. Based on Kirchhoffs theory,the approximate intensity formulas of double-slit diffraction of Gaussian Beam is derived under paraxial approximation with power series expansion methods.

依据基尔霍夫衍射理论，利用幂级数展开的方法推导出旁轴条件下高斯光束双缝衍射的近似光强计算公式，并通过数值计算对双缝衍射的基本特性进行了讨论，得出了与其他文献一致的结论，得出了高斯光束下的双缝衍射极小值点比平行光束双缝衍射的极小值点向外移，观察屏中心光能变小；光强分布可由激光斑在衍射屏处的参数调制的结论。

A magma ''Q'' is a quasigroup precisely when these operators are bijective. The inverse maps are given in terms of left and right division by

原群 ''Q''是拟群当且仅当这两个变换是双射变换，而且它们的逆变换给出了右除和左除变换

Based on Matlab, simulation program of grating diffraction is complied. By changing adjustable parameters, computer simulations of white light interference and diffraction experiments (i. e., grating diffraction, single slit and double-slit diffraction, double-beam and multi-beam interference experiments) can be achieved.

基于Matlab软件编写出白光光栅衍射仿真程序，通过改变可调参数实现白光干涉、衍射实验（包括：光栅衍射、单缝及双缝衍射、双光束及多光束干涉等）的计算机仿真。

Our method can avoid fold-overs by the stereographic projection and always yields bijective mappings.

该方法能够避免立体投影出现三角形折叠的情况，保证最后的映射是双射。

We introduce some concepts, such as yon Neumann algebras, factor von Neumann algebras, nest algebras and so on, and give some well-known theorems that we will use in this paper. In Chapter 2, we put our attention on linear maps that preserving zero Jordan triple product on nest subalgebrasof factor yon Neumann algebras.

第二章首先对因子von Neumann代数中套子代数上保Jordan三重零积的线性映射进行了研究，证明了从因子von Neumann代数中套子代数到任一有单位元的Banach代数的保Jordan三重零积的单位线性双射是Jordan同构。

The two-photon absorption cross-sections of these styryl derivatives were determined by Z-scan technique, and the benzothiazolium derivatives exhibited the largest TPA cross-sections (10〓s·cm〓/photon) and the best power limiting ability at high operable incident intensity. The results show that the benzothiazolium derivatives are promising organic compounds as two-photon absorption optical limiting materials. 2. Several organic dyes active to 800nm femtosecond laser with D-π-A structure were designed and synthesized.

研究了它们的上转换荧光、上转换激射和光限幅行为，通过改变染料分子共轭体系的大小，首次实现了在576nm-635nm范围内的双光子上转换激光波长的调节，其中噻唑啉碘盐类二苯乙烯化合物的双光子上转换激射峰（576nm）是迄今在1064nm皮秒激光作用下能够得到的最短波长的激光；阴离子显著改变上转换激射效率，但对上转换荧光峰和激射峰的位置影响很小；增加溶液的浓度，上转换荧光光谱和激射光谱红移，并在一定的浓度范围内，能够有效的提高上转换激射效率；利用Z-扫描技术测定了染料分子的双光子吸收截面，发现苯并噻唑类染料分子的双光子吸收截面高达10〓s·cm〓／photon，而且在较大的入射光强范围内，这类染料分子具有较大的光限幅能力，是一类作为双光子吸收光限幅材料很有潜力的染料分子。

It is treated with six fields (Anterior, Posterior, four obliques) positioned 60° apart around the circumference of the patient, each dual field is made up of two component beams, pointing ±15° with respect to the horizontal. The nominal energy of electron beam produced by Mevatron Ⅻ is 3MeV, and the patient is treated at a distance of 3 meters. Using Capintec dosemeter and PS-033 electron beam chamber for measurement, one moniter unit of radiation is equivalent to 0.0127cGy. Measurement of electron energy by Kodak X-omat-V verification film inside the Rando phantom at 100 cm SSD was 3.70MeV, electron energy measured at 3 meters was 3.51MeV. X-ray contamination was measured as 9.5% per six dual fields.

此种方法分别使用六个双照野，由病人的前、后、左前、右前、左后、右后各间隔60度共六个方向照射，每一双照野由水平向上和向下15度照射；荣民总医院选择3MeV电子射束来治疗病人，治疗距离为3公尺，利用擬人假体及柯达X-omat-V验证片实验得电子射束初始能量从3.7Mev变为3.51MeV，六个双照野之X光污染共达9.5%，使用Capintec剂量表及PS-033型电子射束用游离腔测量六个双照野，每一监测单位相当於0.00127 cGy。

The apparatus comprises a first RF switch separating a received signal into N communication services; M diplexers associated with the communication services, for separating a signal received from the first RF switch into a call signal and a TV signal; a second RF switch for applying the TV signal received from the diplexers to a TV tuner; and a controller for controlling an overall operation of the multimode mobile phone and controlling the first RF switch and the second RF switch according to the received signal.

该设备包括第一射频开关，用于将所接收到的信号分离成N个通信服务；M个双工器，该M个双工器与通信服务相关，用于将从第一射频开关所接收到的信号分离成呼叫信号和电视信号；第二射频开关，用于将从双工器所接收到的TV信号提供给TV调谐器上；以及控制器，用于对多模式移动式电话的整个操作进行控制并且根据所接收到的信号来控制第一射频开关和第二射频开关。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。