碱添加量对金属离子的分布和pH变化的影响

提出了一种计算公式,定量地计算了既有氢氧化物沉淀又有氢氧配离子形成的化学反应体系中的金属离子的分布,考察了影响沉淀和配离子形成的各种因素.基于提出的公式,计算了锌、镉、铜、镍、铁（Ⅲ）、铁（Ⅱ）、铝、钙、镁的沉淀率,理论计算与实验结果一致.     

CONFIGURING BOTH BACKBONE AND LOGICAL NETWORKS OF A RECONFIGURABLE NETWORK WITH LINK FAILURES ALLOWED

This paper considers a problem of configuring both backbone and logical networks in a reconfigurable circuit-switched network where links are subject to failures. The objective is to design feasible backbone and logical networks at least cost where the cost includes backbone link capacity expansion cost, lost-call traffic penalty, and hop cost (nodal processing cost). The problem is formulated as a zero-one non-linear mixed integer programming problem, for which a solution procedure is developed by use of a Lagrangean relaxation technique and heuristic methods exploited for improving the lower and upper bounds of any intermediate solution. The solution procedure is tested for its effectiveness with various numerical examples.     

END-WINDING INFLUENCE ON HOMOPOLAR EFFECTS IN ASYMMETRICAL THREE-PHASE MACHINE WINDINGS

ABSTRACT

Asymmetries in three-phase windings of rotating-field a.c, machines may cause homopolar currents in delta-connected phase windings. End-winding particulars can have an Important quantitative influence on these currents and on the connected phase current inequalities.     

Microbiological Evaluation of Alaska Shore-based Surimi Production

Two shore-based surimi plants in Alaska were investigated to determine microbial conditions of Alaska pollock flesh during processing. Median aerobic plate count (APC) was 2.0 × 10³/g after mincing, 2.3 × 10³/g after washing/screening, 4.2 × 10⁴/g after refining and 1.6 × 10⁴/g after dewatering. Reprocessing, needed for nonanalog grade surimi, resulted in APC of 1.2 × 10⁵/g after a second refining and 3.0 × 10⁵/g after a second dewatering. The APC for analog grade surimi was 5.5 × 10⁴/g and 2.0 × 10⁶/g for nonanalog grade surimi. Highest total coliform most probable number (MPN) of > 1100/g was determined from a nonanalog grade surimi sample and from a mince that had been refined twice. Highest Escherichia coli MPN of 460/g was determined from two minces.     

From organ-on-a-chip towards body-on-a-chip

Organ-on-a-chip technology aims to reproduce the key physiological features of human organs and tissues, even complex actions of multi-organ interaction. While organ-on-a-chips at single-organ level has made notable achievement during the last decade, multi-organ-on-a-chips, which manifests unique advantages, has started gathering attention only recently. In this viewpoint, we discuss the current status of organ-on-a-chip technology, with a specific emphasis on multi-organ-on-a-chip. Key technological advances contributing to the maturation of the field, and challenges that need to be addressed before wider adoption in relevant fields are discussed. We will share our perspectives on how the multi-organ-on-a-chip can improve the drug development process.     

锐钛矿和钛铁矿混合型钛矿石的浮选分离研究

对TiO₂品位为13.43%的内蒙古磨石山沉积变质型锐钛矿开展了试验研究。以YS-3为捕收剂的正浮选获得了TiO₂品位37.95%、回收率23.79%的钛精矿; 以NaOH为pH调整剂、淀粉为抑制剂、石灰为活化剂、164为捕收剂的反浮选获得了TiO₂品位30.07%、回收率70.46%的钛精矿。结果表明: 反浮选效果优于正浮选, 能更好实现钛矿物富集。     

JOINT CONFIGURATION OF BACKBONE AND LOGICAL NETWORKS ON A RECONFIGURABLE PACKET-SWITCHED NETWORK WITH UNRELIABLE LINKS

Abstract

This paper considers a problem of configuring both backbone and logical networks in a reconfigurable packet-switched network where links are subject to failures. The objective is to design feasible backbone and logical networks at least cost where the network cost includes backbone link capacity expansion cost and average packet delay penalty cost due to link failures. The problem is formulated as a zero-one non-linear mixed integer programming problem, for which an effective solution procedure is developed by using a Lagrangean relaxation technique for finding a lower bound and a heuristic method is exploited for improving the upper bound of an intermediate solution. The solution procedure is tested for its effectiveness with various numerical examples.     

EFFECTS OF SECONDARY AIR INJECTION ON GAS-SOLID FLOW BEHAVIOR IN CIRCULATING FLUIDIZED BEDS

Effects of secondary air injection on the hydrodynamics such as solid holdup and gas-solid flow behavior were investigated in a circulating fluidized bed. The gas velocity in the riser, the ratio of secondary air velocity to that of primary air, and the solid circulating rate were chosen as operating variables. Fluid cracking catalyst(FCC) with a density of 1840 kg/m³ and a mean diameter of 74 um was employed as the solid phase. The secondary air was fed to the riser radially or tangentially at the wall of the column. Pressure drop fluctuations in the riser were measured and analyzed by adopting the stochastic method to characterize the effects of secondary air injection on the gas-solid flow behavior in the bed.

It has been found that the injection of secondary air into the riser can increase the solid holdup in the riser considerably, and that the tangential injection of secondary air is more effective for the increasing the solid holdup than the radial injection. However, the gas-solid flow behavior has been found to become less persistent with the injection of secondary air; the resultant flow behavior is more complex when the air is injected tangentially than radially. The solid holdups in the primary as well as secondary zones of the riser have been well correlated in terms of not only operating variables but also fractal dimension of the pressure fluctuations.