下界的

On the basis of the theory of option pricing,We study the connection between America call option and European call option;Under the assumption condition of Black-Scholes formula ,use the theory of martingales and stopping time,get the conclusion that: the price of America call option equals the price of European call option; Discuss some numeric computing methods of the put America option pricing, with the invarional inequaility for optimal stopping, prove the boundary property of America put option price ...

基于期权定价的基本理论，研究美式看涨期权与欧式看涨期权之间的关系；在Black-Sc holes公式假设条件下，利用鞅和停时理论，得美式看涨期权的价格与欧式看涨期权的价格相等；探讨美式看跌期权价格的数字化计算，在相关假设条件下，利用基于最优化时的变分不等式证明了美式看跌期权价格的有界性，并介绍了几种美式看跌期权价格的数字化计算方法。

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After preaging at 100℃for 24 h, retrogression at 200℃for 7 min, and reaging at 100℃for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210MPa in 3.0%NaCl+0.5%H2O2corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the microstructure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7 min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720 h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa， 767 MPa和9.1%，显示优越的综合性能。

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After pre-aging at 100 ℃ for 24 h, retrogression at 200 ℃ for 7 min, and reaging at 100 ℃ for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210 MPa in 3.0%NaCl+0.5%H2O2 corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the microstructure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7 min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720 h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa， 767 MPa和9.1%，显示优越的综合性能。

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After pre-aging at 100℃ for 24 h, retrogression at 200℃ for 7 min, and reaging at 100℃ for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210 MPa in 3.0%NaCl+0.5% H2O2 corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the micro- structure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa，767 MPa和9.1%，显示优越的综合性能。

The 0°K relaxed structures of grain boundaries in Cu and its alloys (Cu-Ag, Cu-Bi) were simulated with molecular dynamics method by using a five-parameter potential and constant volume assumption.In these cases, the results showed that the atomic distribution was periodic in the two directions paralled to the grain boundary and it was mirror-symmetric in the direction perpendicular to the boundary.

本文采用五参数对势和固定体积的假定，应用分子动力学方法模拟了零温下纯Cu、Cu-Ag和Cu-Bi合金的晶界弛豫结构，计算结果表明，在上述情况下，原子分布在平行晶界面的两个方向是周期性的，在垂直晶界面的方向是镜面对称的。

On a tour of South East Asia fans received him like a rock star as he played his unique crossover music accompanied by strobe lights and video screens and dates in Japan where he played in a more purely classical style accompanied by the Moscow Symphony Orchestra were greeted just as rapturously.

在巡演中，当他在闪光灯和电视墙下弹奏那独特的跨界音乐时，东南亚的粉丝们为他送上了热烈的欢呼，就好像他是一个摇滚歌星。而在日本举行的音乐会中，在莫斯科交响乐团的伴奏下，他的弹奏风格则更加古典，同样引起了听众的强烈反响。

The new type of writing for the womenfolk in the early 20th century began with the liberation movement of the women in the social background of "Literature Revolutionary" which guided by the new type writing of Liang Qichao.

20世纪初的中国女界新文体，是在"文界革命"的社会背景下，在梁启超"新文体"主张与书写实戏的示范下，随着妇女解放运动的展开而自成其体的。

SEM analysis finds that the fractures are intercrystalline plus quasi-cleavage fractures under quasi-motionless state;with the increase of stress intensity factor,fractureschange from transcrystalline quasieleavage fractutes to microvoid-coalescence dimple plus cleavage frac-tures,The increase of fracture toughHess of 8090Al-Li alloy under high stress intensity factor is associ-ated with the deformation mechanism and the change of precipitation Free Zone of grain boundary.

扫描电镜分析发现，准静态下的断裂为沿晶和准解理混合断口；随着应力强度因于的增加，断裂从准解理断裂过渡到准解理和显微空穴聚集的韧窝断裂舶混合断口。高应力强度因于率下断裂韧度的提高与其变形机制和晶界无沉淀区的变化有关。

Furthermore, a method of calculating mathematic expectation value of exterminating target, the shooting number of times, the minimum time partition between targets, which can guarantee that they would be exterminated on the far boundary of the killing area and in it ,the shooting density under this condition.

文中给出了在两种形式的电子干扰下，某型地空导弹武器系统发现目标能力的计算方法，进而研究了该条件下消灭目标的数学期望值、射击次数、保证目标在杀伤区远界和杀伤区内消灭的目标之间最小时间间隔、射击密度等参数的计算方法。

Its high quality and product features have gained its brand/product recognitions in the refrigeration industry.

在艾默生总部的支持下，在公司全体的共同努力下，沈阳的产品以其独特的性能及优势，一直被制冷界所青睐。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。