InGaAs（P）分别限制应变单量子阱激光器的优化设计

针对较常用的ＩｎＧａＡｓ（Ｐ）分别限制应变单量子阱激光器，给出了为得到最大净增益的优化设计参数。对于激射波长为１．５５μｍ的无应变激光器，最佳的光限制层波长为１．２４μｍ，厚度为１００ｎｍ。当阱材料引入压缩应变后．由于价带的有效状态密度减小，量子阱激光器的微分增益变大，阱深的增大对增大线性增益的效果更加明显．所以最佳光限制层的波长将变短，为１．２０μｍ     

Effects of EGb 761 on nitric oxide and oxygen free radicals, myocardial damage and arrhythmia in ischemia-reperfusion injury in vivo

The cardioprotective effects of EGb 761 on the release of nitric oxide (NO), the concentration of serum thiobarbituric acid reaction substance (TBARS), the activity of creatine kinase (CK) and the incidence of ventricular arrhythmias were investigated in myocardial ischemia-reperfusion injury in vivo. Using sodium nitrite (NaNO2) as standard source of nitric oxide (NO), we compared the correlation coefficients of the three measuring methods used currently in the determination of NOFe2+(DETC)2 complex with that of the measuring method suggested in this study. The result showed that measuring the whole height of three splitting signals is the best linear correlation to the concentration of NO comparing with other methods in this system. Using this method, we observed the effects of EGb 761 on NOFe2+(DETC)2 complex in myocardial ischemia-reperfusion injury in vivo. The hearts of the Wistar rats were subjected to 30 min of ischemia and 10 min of reperfusion in vivo. Different doses of EGb 761 (25, 50, 100, 200 mg/kg i.p.), superoxide dismutase (SOD, 10(4) U/kg), l-arginine (50 mg/kg i.p.) and nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine (NNA, 50 mg/kg i.p.) were administered to the ischemia-reperfusion rats. EGb 761 under the dose of 100 mg/kg increased the signal intensity of NOFe2+(DETC)2 complex, while EGb 761 at 200 mg/kg showed an effect of decreasing the signal intensity of NOFe2+(DETC)2 complex. EGb 761 inhibited the formation of TBARS, the release of CK, and mitigated the incidence of ventricular arrhythmias in a dose dependent way. Both l-arginine and SOD increased the signal intensity of NOFe2+(DETC)2 complex and inhibited the formation of TBARS, the leakage of CK and the incidence of ventricular arrhythmia. NNA not only had no protective effects on myocardial injury, but also increased the incidence of reperfusion-induced arrhythmia. In conclusion, EGb 761 has cardiovascular protective effects by means of adjusting the level of NO and inhibiting oxygen free radicals induced lipid peroxidation in myocardial ischemia-reperfusion injury in vivo.     

As,Sb,Sn对30CrMnSiA钢力学性能的影响

在３０ＣｒＭｎＳｉＡ钢中加入不同量的Ａｓ，Ｓｂ，Ｓｎ元素，研究了这些元素单独存在及复合存在时对钢的强度，塑性，冲击韧度及韧脆转变温度的影响规律，并用扫描电镜及俄歇能谱分析了Ａｓ，Ｓｂ，Ｓｎ导致晶界脆化的机理。     

RFID技术在智能交通管理中应用

本文主要介绍RFDI技术定义及系统工作原理,并重点关注RFID技术在智能交通领域的实际应用方式。同时RFID技术也成功解决了车辆自动识别和信息采集问题,为智能交通管理和服务系统的建立提供了强大的信息支撑和保障。     

Characterization of ultrafine La x Sr1−x MnO3 powder prepared by spray pyrolysis

The characterization of La _x Sr_1−x MnO₃ powders produced by spray pyrolysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observation, specific surface area (Brunauer-Emett-Teller), and particle size distribution measurements shows that the resultant large particles are loose agglomerates consisting of many small particles. However, the sintered tiny particles can form hard agglomerates, and the particle size increases remarkably. The structures of the powders before and after sintering were identified by x-ray diffraction (XRD). The study of the electrical property of the powder shows that the powder is a metallic conductor. In a reducing atmosphere, the powder can be decomposed. When the powder is cofired with yttria-stabilized zirconia 5% (YSZ) powder at 1200 °C for 5 h, no new phase is produced, and the powder remains a single provskite hexagonal-rhombohedral structure.     

Effect of surface free energy on the adhesion of biofouling and crystalline fouling

Pipelines and heat exchangers using seawater as coolant suffer from biofouling. Biofouling not only reduces heat transfer performance significantly, but also causes considerable pressure drop, calling for higher pumping requirements. It would be much more desirable if surfaces with an inherently lower stickability for biofouling could be developed. In this paper, a cost-effective autocatalytic graded Ni-Cu-P-PTFE composite coating with corrosion-resistant properties was applied to reduce biofouling formation. The experimental results showed that the surface free energy of the Ni-Cu-P-PTFE coatings, which were altered by changing the PTFE content in the coatings, had a significant influence on the adhesion of microbial and mineral deposits. The Ni-Cu-P-PTFE coatings with defined surface free energy reduced the adhesion of these deposits significantly. The anti-bacterial mechanism of the composite coatings was explained with the extended DLVO theory.     

无芯胶管的研制、工艺现状和发展建议

20世纪60年代初,我国胶管领域自主开发创新研制了无芯胶管制造技术,并且形成定型技术,一直沿用至今,笔者参与、见证了该产品从试验到投产的全过程。本文对该产品的工艺进行了新旧对比,提出了今后发展的建议。     

结晶性高聚物作为相变材料的应用

本文研究了结晶性高聚物聚乙烯及其共混物作为相变材料对模拟发热体铜片热量的吸收作用，由于相变的吸热，铜片的温度在一定时间范围内保持在一个定值。选择不同的相变材料，可使这种温度平台出现在不同的温度范围，不共晶的共混物可有两个以上的温度平台，提高了降温效果。     

2,6-二乙酰基吡啶合成方法的改进

优化了2，6—二乙酰基吡啶的合成工艺。以2，6—吡啶二羧酸为原料，经过醇化及克莱森酯缩合反应，合成了2，6—二乙酰基吡啶，2，6—吡啶二羧酸二乙醇和2，6—二乙酰基吡啶的分离收率分别为94．1％和88．9％，2，6—二乙酰基毗啶的质量分数大于99％。