Diode Laser Spectroscopy of Trifluoroethylene in the 8.6-μm Region

The two mid-infrared bands of the CF2&dbond;CHF molecule, nu5 centered at 1172.673 cm-1 and nu6 + nu9 at 1155.105 cm-1, were measured on a tunable diode laser spectrometer with a resolution near the Doppler limit. These vibrations of A' species give rise to a/b hybrid bands, even though our analysis has pointed out that the intensity of the a-type component is predominant. Most of the J and K structure has been resolved in different subbranches, and the rovibrational analysis led to the assignment of about 1400 (J 相似文献   

锰硅X荧光光谱分析的研究

选用最佳制样时间控制试样粒度;在一定压力条件下,用特制合金样托压制MnS i试样;采用标样控制仪器状态,分析总量控制分析准确度的方法,提高锰、硅的分析准确度,压片分析值与化学值相比,结果良好。     

Spectrophotometric determination of diphenhydramine. HC1 in pharmaceutical preparations

A new spectrophotometric method has been developed for determining diphenhydramine. HC1, based on solvent extraction into chloroform of the complex formed with bromocresol green. The complex solution in chloroform showed maximum absorption at 415 nm and obeyed Beer's law over the concentration range of 3.0-12.0 microgram/ml. The molar absorptivity of the complex was 2.02 x 10(4). Complex formation and extraction was complete and quantitative over the pH range from 2 to 5. The ratio of diphenhydramine to bromocresol green was 1:1. Excipients, coloring matter, flavoring agents, and other substances likely to be present in diphenhydramine preparations do not interfere in the determination. Direct determinations in tablet, capsule, sirup, and lotion preparations were carried out satisfactorily, and the average recovery was 100 +/- 1.0%.     

Dissimilar Laser Joining of NiTi SMA and MP35N Wires

The laser welding of NiTi alloy wire to MP35N wire was investigated to improve the understanding of dissimilar materials joining of NiTi shape memory alloys (SMAs), facilitating their future application in novel devices. Both positioning of the laser beam with respect to the joint’s centerline and laser peak power were found to be critical variables affecting the physical and thermomechanical properties of the welded joint. Positioning of the laser beam was used to control the weld pool composition, while the laser beam intensity affected the pool size and mixing. These variables were shown to greatly affect hardness and susceptibility to cracking in the fusion zone, which heavily impacted the weld strength. With a lower peak power and the laser positioned over the MP35N wire, butt-welded wire joints were achieved with the ultimate load of 66 pct of the NiTi wire breaking load.     

武钢一冷轧HC可逆式轧机厚度控制系统分析

厚度精度是冷轧带钢最重要的质量指标之一,为实现对冷轧带钢厚度的自动控制,HC可逆式轧机引入了厚度控制系统,通过多种AGC方式的综合运用,提高了尺寸精度的命中率。本文介绍了武钢HC可逆式轧机厚度控制系统的工作原理和应用效果。     

Diode Laser Assisted Surface Nitriding of Ti-6Al-4V: Properties of the Nitrided Surface

In the present study, a detailed investigation of mechanical and electrochemical properties of laser-surface-nitrided Ti-6Al-4V has been carried out. Laser treatment is carried out by melting the surface of Ti-6Al-4V substrate using a high power CW diode laser with nitrogen as shrouding environment. The effect of laser parameters (applied power and gas flow rate) on the properties of the nitrided surface was evaluated. The microhardness of the nitrided surface was improved to a maximum of 1175 VHN in the present set of laser processing conditions as compared to 280 VHN of as-received substrate. Surface nitriding increased the potential for pit formation (E _pit) significantly as compared to as-received Ti-6Al-4V. Immersion in Hank’s solution showed calcium phosphate deposition from the solution. The optimum process parameters for laser surface nitriding were derived.     

Determination of distances from tyrosine D to QA and chlorophyllZ in photosystem II studied by ''2+1'' pulsed EPR

The immunomodulating effect of a new polysaccharide-peptide complex from culture mycelia of Lentinus edodes (LE) was studied for elucidation of the mechanism of augmentation of cell-mediated immunity. RNA samples were isolated from the untreated and treated murine splenocytes and human peripheral blood mononuclear cells. RT-PCR was used to analyze the cytokine gene expression and bioassay was used to analyze the cytokine production. By administration of LE, the expression levels of IL-2 and TNF-alpha genes were augmented in the treated murine spleen mononuclear cells and human peripheral blood mononuclear cells. The production of IL-2 were augmented in the treated murine spleen mononuclear cells, and the production of TNF-alpha were augmented in the treated murine peritoneal exudate macrophages. The production of IL-2 and TNF-alpha were augmented in the treated human peripheral blood mononuclear cells. These results suggest that LE may induce Th immune responses.     

Fourier Transform Emission Spectroscopy of the A'' 1Pi-X1Sigma+ and A1Pi-X1Sigma+ Systems of IrN

The gene coding for the 3C protease from human rhinovirus strain 1B was efficiently expressed in an Escherichia coli strain which also overexpressed the rare argU tRNA. The protease was isolated from inclusion bodies, refolded, and exhibited a kcat/Km = 3280 M-1 s-1 using an internally quenched peptidyl fluorogenic substrate. This continuous fluorogenic assay was used to measure the kinetics of 3C protease inhibition by several conventional peptidyl chloromethylketones as well as a novel series of compounds, the bromomethylketonehydrazides. Compounds containing the bromomethylketonehydrazide backbone and a glutamine-like side chain at the P1 position were potent, time-dependent inhibitors of rhinovirus 3C protease with kinact/Kinact values as high as 23,400 M-1 s-1. The inhibitory activity of compounds containing modified P1 side chains suggests that the interactions between the P1 carboxamide group and the 3C protease contributes at least 30-fold to the kinact/Kinact rate constants for bromomethylketonehydrazide inhibition of 3C protease. Electrospray ionization mass spectrometry measurements of the molecular weights of native and inhibited 3C protease have established an inhibitory mechanism involving formation of a covalent adduct between the enzyme and the inhibitor with the loss of a bromide ion from the bromomethylketonehydrazide. Tryptic digestion of bromomethylketonehydrazide-inhibited 3C protease established adduct formation to a peptide corresponding to residues 145-154, a region which contains the active site cysteine-148 residue. The bromomethylketonehydrazides were fairly weak inhibitors of chymotrypsin, human elastase, and cathepsin B and several of these compounds also showed evidence for inhibition of human rhinovirus 1B replication in cell culture.     

Pulvermetallurgisch durch heißisostatisches Pressen hergestellter Warmarbeitsstahl X 40 CrMoV 5 1

Die Verfahrensparameter für die heißisostatische Pulververdichtung des Warmarbeitsstahles X 40 CrMoV 5 1 (Werkstoffnummer 1.2344) werden aus der Beurteilung der mechanischen Festigkeitswerte sowie des Bruch- und Schliffgefüges festgelegt. Hierbei erweist sich die Schlagbiegearbeit der ungekerbten Probe als besonders kritische Meßgröße zur Optimierung der einzelnen Prozeßschritte. Die am PM-Stahl ermittelten statischen und dynamischen Festigkeitswerte werden den Werten der konventionellen SM-Legierung gegenübergestellt.     

一种不带隔离装置的18脉波二极管整流电路分析

提出了一种不带控制开关、比较经济的三相AC/DC接口电路.关键是把没有带隔离装置的移相变压器与带分接二极管的相间电抗器相结合起来.得到交流侧产生的18脉波电流中谐波总量为10.11%,接近12脉波电路的2/3.