新型高温永磁体的研制

通过分析影响磁体高温性能的因素,设计了新磁体的成分为:Cu含量高,Fe含量低,Zr适量,Sm含量高;采用粉末冶金工艺制备了高温Sm_2(CoFeCuZr)_(17)永磁体。制得的磁体室温磁性能为:B_r1.075 T,H_(ei)2 098.2 kA/m,H_(eb) 776.1 kA/m,H_k843.8 kA/m,(BH)_(max)210.0 kj/m~3;在200℃时的磁性能为:B_r0.991 T,H_(ci)1 175.7 kA/m,H_(cb)531.7 kA/m,H_k577.9 kA/m,(BH)_(max)172.5 kJ/m~3;矫顽力温度系数β(20～200℃)为-0.24％/℃。经理论分析和实验验证,磁体的使用温度均超过400℃,为高温环境(高于400℃)提供了一种实用性永磁材料。     

聚酯装置熔体过滤器的国产化改造

熔体过滤器为聚酯装置关键设备,其国产化问题一直未能解决。该文通过对天津分公司200kt/a聚酯装置熔体过滤器改造方案的介绍,探讨了其国产化条件,分析了国产熔体过滤器的结构特点,并与进口过滤器进行了对比,提出了一些看法。     

结构安全性综合评估方法的研究

已有结构的安全性的评估是关系到社会经济、安全的重大问题。本文作者从临界结构入手，以构件失效影响面积为参考，得到了计算构件重要性系数的简便方法，结合构件的可靠度提出了定性与定量结合的结构安全性综合评估方法。从工程实例来看，本文提出的方法简单实用，与现行的鉴定标准符合得比较好。     

Reconstruction of reflectance spectra using weighted principal component analysis

The weighted principal component analysis technique is employed for reconstruction of reflectance spectra of surface colors from the related tristimulus values. A dynamic eigenvector subspace based on applying certain weights to reflectance data of Munsell color chips has been formed for each particular sample and the color difference value between the target, and Munsell dataset is chosen as a criterion for determination of weighting factors. Implementation of this method enables one to increase the influence of samples which are closer to target on extracted principal eigenvectors and subsequently diminish the effect of those samples which benefit from higher amount of color difference. The performance of the suggested method is evaluated in spectral reflectance reconstruction of three different collections of colored samples by the use of the first three Munsell bases. The resulting spectra show considerable improvements in terms of root mean square error between the actual and reconstructed reflectance curves as well as CIELAB color difference under illuminant A in comparison to those obtained from the standard PCA method. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 360–371, 2008     

高水头弧形闸门伸缩式水封的黏弹性仿真计算方法

认为止水材料的蠕变和应力松弛是由于材料参数的变化而引起的，把描述橡胶类材料应变能密度函数中的物理参数假设成与时间有关的黏弹性函数。在此基础上改进材料应力张量与应变张量的关系式，得到了改进的Mooney-Rivlin公式，给出了一种考虑止水材料黏弹性性质的伸缩式水封仿真计算方法。分析得出，止水材料由于受周边结构的限制，材料黏弹性阶段除顶点垂直位移不变，关键结点的其它位移并没有因材料的蠕变而显著变化，材料的蠕变有提高封头顶点接触应力的趋势，不会降低水封的水密性。通过工程实例，给出了140m水头下、封头与面板间隙控制在30mm内的可行并较优的伸缩式水封的断面。     

Data decomposition using independent component analysis with prior constraints

In many data analysis problems, it is useful to consider the data as generated from a set of unknown (latent) generators or sources. The observations we make of a system are then taken to be related to these sources through some unknown function. Furthermore, the (unknown) number of underlying latent sources may be less than the number of observations. Recent developments in independent component analysis (ICA) have shown that, in the case where the unknown function linking sources to observations is linear, such data decomposition may be achieved in a mathematically elegant manner. In this paper, we extend the general ICA paradigm to include a very flexible source model, prior constraints and conditioning on sets of intermediate variables so that ICA forms one part of a hierarchical system. We show that such an approach allows for efficient discovery of hidden representation in data and for unsupervised data partitioning.     

新型引线热浸镀锡合金的研究

分析比较了进口锡与国产锡的成分和性能。设计出了新型的引线热浸镀锡合金，它具有较低的工作温度、优良的抗氧化性、流动性和可焊性。     

一种新型图形描述算法

本文提出一种新型的图形描述算法，该算法以各种规则图形作为图形的最小处理单位。利用本算法构造的图形管理系统可广泛用于环境实时监控、采样数据动态显示等领域     

On the algebraic formulation of certain geometry statements and mechanical geometry theorem proving

In this paper we analyze the algebraic formulations of certain geometry statements appearing in recent literature related to mechanical geometry theorem proving and give several examples to show that one of these formulations can cause serious problems. We clarify a formulation which is essentially due to W. T. Wu and, in our opinion, is the most satisfactory.This author was supported by NSF Grants DCR-8503498 and CCR-8702108.     

一种适合于同杆4回线的故障测距方法

在对同杆4回线解耦的基础上，提出了一种适合于同杆4回线的故障测距方法。同杆4回线内部发生故障时，可以将故障分量分解为12序分量，且利用该12序分量进行故障测距。考虑到在任何故障类型下，同杆4回线内部都会存在反序分量，所以提出了基于反序环流分量的故障测距方法。当同杆4回线内部发生故障时，从线路两端计算到故障点的反序环流分量电压相等，利用该关系可以求出故障点的精确位置。由于相互独立的12序分量完全能够解决线间耦合问题，文中提出的测距算法能够精确测距，测距精度不受故障类型影响。大量ATP仿真结果表明所提出的测距算法完全适用于同杆4回线的故障测距，测距精度不受过渡电阻、系统运行方式、线路两端功角的影响。