大子代数中的极大幂零理想和代数同构

§ 1　Introduction and preliminariesLet Hbe a complex Hilbertspace,B(H) be the setof all linear bounded operators.A set Nofprojections on His called a nestif(1 ) Nistotally ordered by the usual oper-ator order,(2 ) Ncontains the zero operator0 and the identity operator I,and(3 ) givenany subset N0 N,the operators sup{ N:N∈N0 } and inf{ N:N∈ N0 } are both mem-bers of N.For N∈Nwith N>0 ,we define N- =sup{ N′∈N:N′相似文献   

铀与UO2表面铝薄膜生长行为的俄歇电子能谱分析

主要利用俄歇电子能谱（AES）原位分析了室温下铀与UO2表面铝薄膜的生长行为。在俄歇电子能谱仪超高真空室中，利用Ar^＋枪溅射铝靶，使其沉积到铀基体上，然后利用电子枪适时采集表面俄歇电子能谱，原位分析铝薄膜的生长过程。在UO2表面沉积铝膜时，先往真空室中充入氧气，将清洁铀表面氧化成UO2，然后再溅射铝靶原位沉积制备铝薄膜。     

Effect of speckle pattern on laser Doppler velocimeters

The effect of speckle pattern on laser Doppler velocimeters is studied theoretically and experimentally. We have found that dynamic speckle patterns can cause error in velocity measurement. Increasing sampling time and using proper signal processing circuits can eliminate this bad effect caused by speckle pattern. The accuracy of velocity measurement is better than 2.1% in a wide velocity range (4.66-468.86 mm/s) when speckle effects are taken into account.     

不同粉料制备Nd∶(Y_(0.9)La_(0.1))_2O_3透明陶瓷及其性能

分别采用液相法和固相法制备的纳米粉,制得透明性良好的Nd∶(Y0.9La0.1)2O3透明陶瓷,并测试了各样品的结构,光谱及光学性能.结果表明:该陶瓷具有相同的光谱性能;但液相法复合纳米粉制备的透明陶瓷光学性能优于固相反应法制备的透明陶瓷;固相反应法制备的透明陶瓷,由于有部分La2O3分布不均,易导致晶粒生长不均匀和残留少量气孔;长时间球磨混料,也不利于样品性能的提高.     

长基线组合解测向模糊

在证明了多基线的相位干涉仪不产生测向模糊的充要条件后,讨论了两种用长基线组合解测向模糊的算法.通过对存在测量误差情况下正确解模糊条件的分析,提出了避免错误解模糊的方法.对两种算法的解模糊容差的比较,显示了两种方法的性能,为综合使用这两种方法提供了依据.文中的例子也有助于对多基线组合解测向模糊方法的了解.     

相对论重离子碰撞中粒子产生和/比率

利用强子输运 -弦碎裂模型研究了 2 0 0AGeV重离子碰撞中 Λ多重产生和 Λ / p比率 .研究了它们随反应系统大小和碰撞中心度的变化 .研究表明 Λ和 p多重数都随反应系统增大和随碰撞中心度提高而增大 ,但它们的比率基本保持不变 . Λ的湮没截面大小变化对 Λ的多重数产生有一定影响 ,但对 Λ / p比率影响不大 .结果很好地再现了 pp反应中 Λ/ p比率 .并获得这一比率在AA反应中是pp反应中的 3— 5倍     

高效液相色谱串联质谱法测定动物源性食品中苯佐卡因、利多卡因

建立高效液相色谱串联质谱法检测动物源性食品中的苯佐卡因、利多卡因残留量的分析方法。称取粉碎后的样品5.0 g,置于50 mL离心管中,加入1 g NaCl,10 mL乙腈,振荡提取20 min后,以4 500 r/min转速离心5 min,取上清液6 mL,分别加入乙二胺-N-丙基硅烷(pPSA) 50 mg、C₁₈ 50 mg,然后在涡旋仪上涡旋1 min,以4 500 r/min转速离心5 min,然后取0.5 mL上清液与0.5 mL复溶液[0.1%甲酸-乙腈(体积比为80∶20)混合液]混合,过0.22μm滤膜,供高效液相色谱串联质谱法测定。以0.1%乙酸-乙腈为流动相,C₁₈柱为色谱柱,多反应监测模式分析,色谱峰面积外标法定量。苯佐卡因和利多卡因在0.1～50.0μg/L的质量浓度范围内线性关系良好,相关系数均大于0.999,检出限分别为0.2、0.1μg/kg,定量限分别为0.7、0.5μg/kg,回收率分别为85.0%～100.6%、87.7%～99.8%,5次测定结果的相对标准偏差分别为0.3%～3.5%、1.8%～3.6%。...     

基于三元非富勒烯体系的高效有机太阳能电池

有机材料的"窄吸收"特性制约了有机太阳能电池(OPVs)性能的进一步突破,二元体异质结薄膜难以实现对太阳能的有效宽光谱利用.三元OPVs在二元体系中引入吸收互补的第三组分,能够增强器件光吸收,实现光电转化效率的大幅提升.近年来,非富勒烯受体材料的飞速进展,多次刷新有机太阳能电池最高效率记录,丰富并扩展了三元受体材料的选择范围.本文以非富勒烯受体材料Y6作为第三组分材料,高效率非富勒烯太阳能电池PBDB-T-2F:IT-4F作为基础二元器件,研究并分析了以双非富勒烯材料为受体的三元有机太阳能电池工作机理.通过光电特性分析,发现Y6的引入不仅能够增强器件近红外区域的光吸收能力,而且能够有效抑制双分子复合,提高电荷取出率,从而提高器件能量转换效率.通过调节Y6在三元体系中的质量百分比,在Y6占比为20 wt%时,器件实现最高的能量转换效率12.48%,相比于基础二元器件(10.59%)实现了17.85%的性能提升.     

Tuning of the Magnetic Damping Parameter by Varying Cr Composition in Fe_(1-x)Cr_x Alloy

We investigate the magnetic damping parameter of Fe_1-xCr_x thin films using the time-resolved magneto-optical Kerr effect technique.It is demonstrated that the overall effective damping parameter is enhanced with the increasing Cr concentration.The effective damping at high field α₀ is found to be significantly enhanced when increasing the Cr concentration with the α₀=0.159 in the Fe₄₅Cr₅₅ enhanced by 562% compared with that of α     

A transient process observation method based on the non-homogeneous Poisson process model

The current-mode-counting method is a new approach to observing transient processes,especially in transient nuclear fusion,based on the non-homogeneous Poisson process(NHPP)model.In this paper,a new measurement process model of the pulsed radiation field produced by transient nuclear fusion is built based on the NHPP.A simulated measurement is performed using the model,and the current signal from the detector is obtained by simulation based on Poisson process thinning.The neutron time spectrum is reconstructed and is in good agreement with the theoretical value,with its maximum error of a characteristic parameter less than 2.3%.Verification experiments were carried out on a CPNG-6 device at the China Institute of Atomic Energy,with a detection system with a nanosecond response time.The experimental charge amplitude spectra are in good agreement with those obtained by the traditional counting mode,and the characteristic parameters of the time spectrum are in good agreement with the theoretical values.This shows that the current-mode-counting method is effective for the observation of transient nuclear fusion processes.