Testing inequality constraints in a linear regression model with spherically symmetric disturbances

This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances, and derive the distributions of the test statistic under null and nonnull hypotheses. The power of the test is then discussed. Numerical evaluations are also carried out to examine the power performances of the test for the case in which errors follow a multivariate student-t （Mt） distribution.     

加工番茄果秧分离技术发展现状分析

介绍了国内外加工番茄收获机械实现果秧分离的方法,即梳齿法、机械手采摘法和振动分离法等,着重对目前应用较为普遍的带式振动分离机构和偏心块式振动分离机构的结构、工作原理及特点进行了分析,并结合W-W型非圆齿轮行星轮系运动特点,进而提出了利用W-W型非圆齿轮行星轮系取代现有机构,实现加工番茄果秧有效分离的方法。     

Changes in intracellular pH and cell volume during the early phase of DMSO-induced differentiation of Friend erythroleukemia cells

Changes in intracellular pH and water volume were measured after treatment of Friend erythroleukemia cells with 1.5% DMSO. It was found that a continuous decrease in pHi occurred, beginning 1 h after induction and a decline in pHi of 0.18 was measured after 9 h. In addition a decline in cellular water volume, of 12% only 15 min after induction, and 23% after 9 h, was observed.