一类正规矩阵的反问题

In this paper, we consider the inverse problems for a kinds of normal matrices. Some necessary and sufficient conditions for existence of solution of these problems are given. The expression of the general solution is given.     

The Stability of Quaternion Metrices and Their Judging Criteria

Some conceptions of stable quaternion matrices and some judging criteria are given.The Robrach theorem,Taussky theorem,Ostrowski Schneider theorem and Gerschgorin theorem are generalized to quaternion field.The conclusion about two quaternion matrices,i.e.,inferior positive matrices are unstable,interior negative matrices are stable and some other results are pointed out.     

AX=b在逆M-阵类中的反问题

将线性方程组 Ａ Ｘ＝ ｂ 分为５ 种情况（ Ｘ＞ ０、 Ｘ≥０、 Ｘ＜ ０、 Ｘ≤０、 Ｘ 为一般情况），通过构造矩阵的方法，讨论了该线性方程组的反问题在逆 Ｍ－ 阵类中有解的条件．在一般情况下，当给定的实向量 Ｘ 与ｂ 中相应的分量同号时，则线性方程组 Ａ Ｘ＝ ｂ 在逆 Ｍ － 阵类中的反问题有解．     

THE INFLUENCE OF TYLOSES ON THE MANUFACTURE OF MATCHES

This article deals with the results of time studies of pruning P. radiata from 22 ft. to 35 ft. with pole saws. The influence on pruning time of mean diameter and number of branches removed in the pruning operation, number of cones removed and time of day is investigated and a multiple regression equation, expressing the relationship between pruning time and these variables, is computed. A taper table is prepared and used to investigate the effect of pruning on the formation of knot-free timber. The economics of high-pruning is discussed.     

固定化酶载体的研究现状及其应用

研制开发性能优异的固定化载体,已成为固定化酶技术最为活跃的研究方向之一。固定化酶在生物及生物工程、环境化工、食品、医药等领域得以迅速发展,其中,结合现代分析仪器,固定化酶反应器(IMER)将成为固定化酶应用的一个新领域。本文对近几年来固定化酶载体的制备及固定化酶的应用进行了综述。     

Alternative matrices for cortisol measurement in fish

Plasma cortisol is the most commonly used indicator of stress in fish but, as the blood sampling procedure itself can be a source of stress, it would be helpful to measure cortisol using less invasive matrices. It is also necessary to find alternative matrices as stress indicators in dead fish in which blood sampling is impossible. In the present study, we investigated transport stress in three aquaculture species, European sea bass (Dicentrarchus labrax L.), common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss Walbaum), by cortisol determination (radioimmunoassay) in plasma and other matrices (skin mucus, gut content, lateral muscle and caudal fin). Cortisol significantly increased after transport in all species and matrices, except in the sea bass gut content, where it remained unchanged. The three species responded to transport stress by producing different cortisol levels. In conclusion, the significant correlation found between plasma cortisol and most of the other matrices opens up the possibility of using them to evaluate stress in fish: mucus sampling is a less invasive method than blood sampling, and in addition to muscle and fin sampling, it can be used in postmortem fish.     

可变参数LESLIE矩阵模型在豆蚜种群动态模拟中的应用

应用室内饲养观察和田间调查数据拟合了豆蚜Ａｐｈｉｓｃｒａｃｃｉｖｏｒａ种群动态的Ｌｅｓｌｉｅ矩阵模型．模型考虑了温度和湿度对种群的影响，用该模型模拟特定条件下豆蚜未来种群的数量和年龄分布，可靠率达７０％．     

不同生长激素和基质对张氏红山茶扦插繁殖影响的研究

对珍稀濒危植物张氏红山茶进行了扦插繁殖试验。结果表明,不同生长激素和浓度的扦插基质对张氏红山茶的扦插生根率有显著影响,其中以红泥∶泥炭∶珍珠岩配比(质量比2∶2∶1)的基质,以1 200倍根太阳或50 mg/kg速生根处理插穗其生根率均可达90%左右,而扦插时期的选择对其生根率影响不大。