子可加性

We show that Jordan multiplicative bijective maps on prime operator algebrasmust be additive. As its application, we show that every Jordan * multiplicative bijec-tive map on every factor C~* algebra is a C~* isomorphism or a conjugate C~* isomorphism,in the special case of B, it must be a *-isomorphism or a conjugate *-isomorphism.We also prove the additivity of Jordan multiplicative bijective maps on nest algebras.

证明了素算子代数上Jordan可乘双射的可加性，利用这一结论刻画了因子C~*代数上的Jordan*可乘双射，我们的结果表明这样的映射一定是C~*同构或共轭C~*同构；证明了套代数上的Jordan可乘双射的可加性。

We discuss the relation between elementary maps and ring isomorphisms, andwe give a characterization of elementary maps on stndard operator algebras on Banachspaces, JSL-algebras and nest algebras. For Jordan-triple elementeary maps, we provetheir additivity on a class of ring and show a relation of them with Jordan isomorphisms. Furthermore. we describe the Jordan elementary maps on standard operator algebrasand nest algebras. We also study the semi-Jordan elementary maps on effect algebrasand the space of self adjoint operators.

研究了算子代数上的初等映射和环同构的关系，完全刻画了Banach空间上标准算子代数，JSL代数和套代数上的初等映射；讨论了Jordan-triple初等映射的可加性以及它和Jordan同构的关系，进而完全刻画了Banach空间上标准算子代数和套代数上的Jordan-triple初等映射；刻画了效应代数和自伴算子空间上的semi-Jordan初等映射。

the paper introduces long curtate new unequal ofdm system.adopts long curtate unequal benefit to be not to require that the second order adding the circulation prefix,being therefore likely to lead into period stationarity,making use of signal therefore in launching an array,counting characteristic property realizing blind estimation of route.this technology includes three kinds of method : subspace decomposition,correlation matching,and maximum likeewise,monte carlo simulation show that whentheeb/no is low,function is better than the other kinds of method.

摘 要：提出一种采用不等长分组新的ofdm系统。采用不等长分组的好处是不需要加循环前缀就能在发射序列中引入周期平稳性，因此，可利用信号的二阶统计特性实现信道盲估计。信道盲估计主要分子空间分解、相关拟合和最大似然三种方法。结合monte carlo仿真表明，在信噪比较低时，结合子空间分解方法计算出的误码性能比其余两种方法好。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。