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11.
西咪替丁的应用进展 总被引:2,自引:0,他引:2
劳英 《宁波大学学报(理工版)》2002,15(2):89-92
综述了近年来国内外报道的H2受体抗拮剂-西咪替丁应用于除治疗消化性溃疡以外的其他疾病的进展情况,以其为临床用药提供参考。 相似文献
12.
本文介绍了差分光学吸收光谱法(DOAS)测量大气污染气体浓度的基本原理。DOAS方法就是利用氙灯发出的紫外—可见光,经望远镜准直后再经过一段距离的传输,由望远镜来接收.在传输中,由于各种不同的分子在不同的波段对光有不同的吸收特征,使光谱具有了污染物的特征,再通过与光源发出的光进行比较,反演这些气体在大气中浓度.我们将DOAS方法应用在监测有机物上,在分析光谱的过程中,应用多项式拟合和最小二乘法,从而精确地从测量光谱中来反演出大气中污染气体的浓度.文中用DOAS方法测量了苯和甲苯的样品,并分析了结果,结果和理论吻合.可为环境中有机污染物监测提供可靠的方法。 相似文献
13.
Atomic layer epitaxy or ALE has proven to be useful for the growth of epitaxial layers of high uniformity, good quality, and
well-controlled thickness. In this study, we have carried out in-situ monitoring during the atmospheric pressure ALE of CdTe on GaAs (100) substrates using spectroscopic ellipsometry (SE). The
susceptor temperature, reactant partial pressures, as well as the flow and flush duration for each precursor are crucial process
variables for ALE growth. Growth was carried out for 20–25 cycles under different sets of these process conditions during
the experiment and in-situ SE was used to verify the presence of layer-by-layer growth, which enabled the quick determination of the process window.
We observed ALE growth of CdTe at 300°C, supporting the explanation that the growth of CdTe occurs via a surface catalyzed
decomposition of the Te precursor di-isopropyltelluride (DIPTe). Investigation of ALE mode growth behavior for different susceptor
temperatures and DIPTe flush times indicated that the growth was limited by competition between desorption and reaction of
the adsorbed DIPTe species on the Cd terminated surface. 相似文献
14.
对现行的森林火情监测方法进行了分析比较。根据实际存在的难题,提出了料为产用的实施方案及应采取的技术措施,进行了实地试验,取得较好的效果。 相似文献
15.
Hee Seok Choi Young Han Kim Shun Myung Shin 《Journal of polymer science. Part A, Polymer chemistry》2006,44(8):2428-2439
An in‐line monitoring device using a quartz crystal resonator for thin film polymerization was proposed, and its performance has been evaluated by implementing in the UV polymerization of 2‐hydroxyethyl methacrylate with a photoinitiator of 1‐chloroanthraquinone. Because the variation of resonant resistance of the resonator is proportional to the square root of viscosity change that is closely related to the polymerization degree, the resistance can be used as a measure of the polymerization degree. The resistance measurements were compared with the outcome of instrumental analyses of polymerization degree using an FTIR spectrometer and a gel permeation chromatograph. The experimental results showed that the resistance measurements were consistent with the experimental outcome of the instrumental analyses, and this indicates the effectiveness of the proposed device. Owing to the simplicity and availability of the resonator system, its wide utilization in the monitoring of a variety of film polymerization processes, including photoresistor application, is expected. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2428–2439, 2006 相似文献
16.
J. Bajaj S. J. C. Irvine H. O. Sankur Spyros A. Svoronos 《Journal of Electronic Materials》1993,22(8):899-906
An effective way to in situ monitor the metalorganic chemical vapor deposition (MOCVD) of HgCdTe/CdTe/ZnTe on GaAs or GaAs/Si
substrates is presented. Specular He-Ne laser reflectance was used to in situ monitor the growth rates, layer thickness, and
morphology for each layer in the grown multilayer structure. In situ monitoring has enabled precise measurements of ZnTe nucleation
and CdTe buffer layer thicknesses. Monitoring the constancy of reflectance during the thicker CdTe buffer growth where absorption
in the CdTe reduces reflectance to just the surface component has led to optimum buffer growth ensuring good quality of subsequently
grown HgCdTe. During the interdiffused multilayer process (IMP) HgCdTe growth, because multiple interfaces are present within
the absorption length, a periodic reflectance signal is maintained throughout this growth cycle. A theoretical model was developed
to extract IMP layer thicknesses from in situ recorded experimental data. For structures that required the growth of a larger
band gap HgCdTe cap layer on top of a smaller band gap active layer, in situ monitored reflectance data allowed determination
of alloy composition in the cap layer as well. Continuous monitoring of IMP parameters established the stability of growth
conditions, translating into depth uniformity of the grown material, and allowed diagnosis of growth rate instabilities in
terms of changes in the HgTe and CdTe parts of the IMP cycle. A unique advantage of in situ laser monitoring is the opportunity
to perform “interactive” crystal growth, a development that is a key to real time MOCVD HgCdTe feedback growth control. 相似文献
17.
18.
Maiorova N. A. Khazova O. A. Tarasevich M. R. 《Russian Journal of Electrochemistry》2004,40(10):1060-1065
The kinetics of the hydrogen oxidation and the CO adsorption on a Pt (ultra)microelectrode is studied in a 0.5 M H2SO4 solution saturated with a mixture of gaseous H2 and CO at partial CO pressures p
CO = 10–500 ppm. The balance between rates of diffusion and adsorption of CO at different adsorption times is studied. Studied is the effect of CO impurities in H2 on steady-state polarization curves for the hydrogen ionization and nonsteady-state curves of the oxidation current decay with time at 0.02–0.05 V. Conditions under which in a certain time interval and at a certain CO concentration the slope of an I vs. t curve is proportional to p
CO are determined. The obtained dependence may be used when designing a technique for monitoring CO impurities in technical hydrogen. 相似文献
19.
Jocelyn Jalbert Roland Gilbert Pierre Tétreault Brigitte Morin Denise Lessard-Déziel 《Cellulose (London, England)》2007,14(4):295-309
In this study, headspace gas chromatography/mass spectrometry has been used to assess the volatile by-products generated by
the ageing of oil-impregnated paper insulation of power transformers. Sealed-glass ampoules were used to age under oxidative
conditions 0.5-g specimens of insulating paper in 9 mL of inhibited mineral oil in a temperature range of 60–120 °C and moisture
of 0.5, 1 and 2% (w/w). A linear relationship between one of the oil-soluble degradation by-products, i.e. methanol, and the
number of ruptured 1,4-β-glycosidic bonds of cellulose, regardless of the type of paper (ordinary Kraft or thermally-upgraded
(TU) Kraft paper), was established for the first time in this field. Ageing at 130 °C of model compounds of the Kraft paper
constituents (α-cellulose, hemicellulose and lignin) and two cellulosic breakdown by-products (D-(+)-glucose and 1,6-anhydro-β-d-glucopyranose) confirmed that the α-cellulose degradation was mostly responsible for the presence of this molecule in the
system. Furthermore, additional 130 °C-tests with six different papers and pressboard samples under a tight control of initial
moisture indicated that at least one molecule of methanol is formed for each rupture of 1,4-β-glucosidic bond of the molecular
chains. Stability tests showed that the ageing indicator is stable under the oxygen and temperature conditions of open-breathing
transformers. The presence of methanol was detected in 94% of oil samples collected from over than 900 in-service pieces of
equipment, confirming the potential for this application. Lastly, the tests have shown that oil-oxidation by-products and
TU-nitrogenous agents modify the methanol partitioning coefficients in the paper/oil/air system, which makes their study essential
over a range of field conditions encountered by power transformers. Results are presented and discussed in comparison with
2-furfuraldehyde, which is the current reference in the domain. 相似文献
20.
GC-MS法测定焦化厂气溶胶中多环芳烃 总被引:2,自引:0,他引:2
利用气相色谱-质谱(GC-MS),电子轰击离子化(EI)法测定焦化厂气溶胶中多环芳烃的含量。超声波抽提气溶胶样品,用GC-MS的选择离子监测(SIM)方式测定EPA提出的优先监测的16种多环芳烃的含量。该法的检出限为0.167pg·m~(-3),PAHs的回收率为85.1%~110.5%,相对标准偏差为4.62%~19.4%。应用该法测定气溶胶中PAHs获得满意的结果。 相似文献