Monolithically integrated SQW laser and HBT laser driver viaselective OMVPE regrowth

An AlGaAs/GaAs nan heterojunction bipolar transistor (HBT) laser driver circuit and a pseudomorphic InGaAs/GaAs/AlGaAs graded index single-quantum-well (SQW) laser have been laterally integrated to maintain surface planarity using selective organometallic vapor-phase epitaxy (OMVPE) regrowth of the HBT. The self-aligned HBTs exhibit a DC current gain of 30 and an f_t (f_max ) of 45(60) GHz. The 980-nm lasers exhibit room-temperature threshold current densities as low as 420(320) A/cm² for CW (pulsed) operation. The cavities are 40(7) μm×500 μm and have less than 1(2) Ω of series resistance. SPICE simulations of the integrated driver indicate that operating speeds of over 10 Gb/s are possible     

Relation between Melting and Textural Properties of Process Cheddar Cheese

Meltability and textural characteristics were evaluated in 48 batches of process Cheddar cheese prepared in pilot plant equipment. Correlation between melting spread at 139°C and cohesiveness at 21°C was positive and large. Prolongation of cooking up to 15 min at 74°C lowered meltability and cohesiveness. Within the range of weighted average ages of cheese (3 to 5.8 mo), no relation between melting spread or cohesiveness and age was consistent.     

Molecular alterations in early gastric carcinomas. No apparent correlation with Helicobacter pylori status

The effect of nitric oxide (NO) donors on high-voltage-activated Ca2+ channels in insulin-secreting RINm5F cells was investigated using the patch-clamp technique in the whole-cell configuration. Sodium nitroprusside (SNP, 2-400 microM) induced a dose-dependent reduction in Ba2+ currents with maximal inhibition of 58%. The IC50 for SNP was 45 microM. A different NO donor, (+/-)S-nitroso-N-acetylpenicillamine (SNAP, 500 microM), also produced a 50% decrease in current amplitude. When 200 microM SNP was administered together with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidozoline-1-oxyl-3-oxide (carboxy-PTIO, 300 microM), the Ba2+ current inhibition was lowered to 7%. Administration of 500 microM 8-bromoguanosine 3':5'-cyclic monophosphate sodium salt (8-Br-cGMP) mimicked the effects of SNP, causing a comparable decrease (56%) in peak-current amplitude. When soluble guanylyl cyclase was blocked by 10 microM 1H-[1,2, 4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ), the inhibitory effect of 200 microM SNP was reduced from 39% to 15%. The SNP-induced current decrease was 36% of controls after the blockade of L-type Ca2+ channels and 30% in the presence of 2.5 microM omega-conotoxin-MVIIC. These data indicate that NO inhibits both L-type and P/Q-type Ca2+ channels in RINm5F cells, probably by an increase in the intracellular levels of cGMP. NO may then significantly influence the Ca2+-dependent release of hormones from secretory cells as well as that of neurotransmitters from nerve terminals.     

Effects of cereal breakfasts on postprandial glucose,appetite regulation and voluntary energy intake at a subsequent standardized lunch; focusing on rye products

Background  

Rye products have been demonstrated to lower the acute insulin demand, induce a low and prolonged blood glucose response (high Glycemic Profile, GP) and reduce subclinical inflammation. These products may therefore contribute to a lowered risk of obesity, type 2 diabetes and cardio vascular disease. The objective of the present paper was to evaluate the mechanism for a reduced postprandial insulin demand with rye products, and to explore possible appetite regulating properties.     

Contrast-modified gradient echo imaging using rotary echo preparatory pulses

The use of on-resonance binomial composite pulses in two- or three-dimensional magnetization-prepared gradient-recalled echo magnetic resonance imaging experiments generates rotary echoes, leading to an increase in contrast range that is, in part, determined by the ratio ofT ₂ toT ₁. In comparison with other fast gradient-recalled echo imaging techniques designed for enhancedT ₂ contrast, this method is more robust with respect to radiofrequency field inhomogeneity and less sensitive with respect to motion artifacts. Three-dimensional parametric images may be calculated using least-squares fitting based on a simple model for steady-state longitudinal magnetization during the imaging sequences.     

对一次高频保护跳闸事故的分析

在一次系统故障过程中。输电线路的两套高频保护装置CSL-101B型和LFP-901B型动作行为不一致。本文就此展开分析，以达到正确理解两种保护动作行为的目的。并对加强高频保护的现场管理提出意见。     

Low-energy ion-implantation-induced quantum-well intermixing

In this paper, we present the attractive characteristics of low-energy ion-implantation-induced quantum-well intermixing of InP-based heterostructures. We demonstrate that this method can fulfil a list of requirements related to the fabrication of complex optoelectronic devices with a spatial control of the bandgap profile. First, we have fabricated high-quality discrete blueshifted laser diodes to verify the capability of low-energy ion implantation for the controlled modification of bandgap profiles in the absence of thermal shift. Based on this result, intracavity electroabsorption modulators monolithically integrated with laser devices were fabricated, for the first time, using this postgrowth technique. We have also fabricated monolithic six-channel multiple-wavelength laser diode chips using a novel one-step ion implantation masking process. Finally, we also present the results obtained with very low-energy (below 20 keV) ion implantation for the development of one-dimensional and zero-dimensional quantum confined structures.     

Electrochemical behaviour of 1024 mild steel in slightly alkaline bicarbonate solutions

The electrochemical behaviour of 1024 mild steel electrodes is investigated in the presence of 0.05–0.5 M sodium bicarbonate in aqueous solution at pH 8.9 and 25°C. Voltammograms are obtained with a rotating gold ring-mild steel electrode and the effect of the NaHCO3 concentration, the potential limits and the rotation speed of the disc electrode is considered. The voltammograms display an oxidation peak current at low potentials, a passivity region and a transpassive region at high potentials for the potential sweep in the anodic direction. The oxidation current in the passivity region is practically independent of the applied potential and the NaHCO3 concentration. The rate-determining step of the oxidation reaction in both the oxidation peak current region and the transpassive region is determined.