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81.
光学实验教学法的改进 总被引:5,自引:0,他引:5
对光学实验教学法做了一些改进:1)将单个光学实验划分为相对独立的单元,每个单元用不同的实验方法研究一个待测的物理量或观察分析一个物理现象;2)加强预习报告要求;3)以调整仪器为主的操作考核。 相似文献
82.
城市下水污泥和煤/LPG在循环流化床上的混烧试验研究 总被引:2,自引:0,他引:2
在高6000 mm、直径300mm的循环流化床上进行了含水率为79%的湿污泥与煤/石油液化气(LPG)的混烧试验。试验结果表明:无论用煤还是LPG作为辅助燃料,试验都能在设定的工况条件下稳定运行;向炉内加入石灰石的量达到钙硫摩尔比为3.4∶1时,二氧化硫和氯化氢的排放达标,脱硫效率和脱氯效率分别为75%和94%;在试验中, 烟气中NOx排放、烟气中汞含量和二恶英类排放都不超标;试验产生的飞灰含碳量低,飞灰中痕量元素的浸出毒性不超标;计算表明,如果利用余热干燥污泥和预热空气可有效地减少辅助燃料的消耗量。 相似文献
83.
J. L. Bailly S. Banerjee F. Bruyant B. Buschbeck C. Caso H. Dibon B. Epp A. Ferrando F. Fontanelli T. Gemesy A. Gurtu R. Hamatsu Ph. Herquet T. Hirose J. Hrubec Yu. Ivanysherkov E. P. Kistenev N. Khalatyan S. Kitamura T. Kreuzberger V. Kubik P. Lipa P. K. Malhotra M. Markytan I. S. Mittra L. Montanet G. Neuhofer G. Pinter P. Porth R. Raghavan T. Rodrigo J. B. Singh S. Squarcia U. Trevisan K. Takahashi L. A. tikhonova T. Yamagata G. Zholobov J. Zoll S. A. Zotkin NA EHS - RCBC Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,40(1):13-24
Two particle correlations of hadrons produced in 360 GeV/cpp interactions are investigated in the transverse plane and in rapidity. The data were obtained at the European hybrid spectrometer equipped with a rapid cycling bubble chamber. The observed transverse and rapidity correlations are compared with the one string LUND-and a two string dual parton-model. These models predict in general stronger correlations in the transverse plane and much weaker correlations in rapidity than found in the data. The LUND-FRITIOF-and multichain dual parton models provide a better reproduction of the data, although the agreement is not yet satisfactory. Only the UA5 cluster model GENCL shows agreement with the data. 相似文献
84.
85.
本文将研究一般区域上高维p-Laplacian方程保号解的存在性:{u(x)=0,x∈ЭΩ,-div(φp(■u))=a(x)φp(u++β(x)φp(u-)+ra(x)f(u)),x∈Ω,其中Ω是RN中一个有界且在其边界上光滑的区域,N≥2,1
p-2s,a(x)∈C(Ω,(0,+∞)),u+=max{u,0},u-=-min{u,0},a{x},β(x)∈C(Ω);f∈C(R,R)对于s>0,sf(s)>0成立.当f0■(0,∞)或f∞∈(0,∞)(其中f0=|s|→0limf(s)/φp(s),f∞=|s|→+∞limf(s)/φp(s)),且r≠0属于一定区间时,可以获得上述高维p-Laplacian方程保号解的存在性.我们用全局分歧技巧和连通序列集取极限的方法获得主要结果. 相似文献
86.
Huetz P Kamarulzaman EE Wahab HA Mavri J 《Journal of chemical information and computer sciences》2004,44(2):310-314
In this article we study the chemical reactions between guanine and two ultimate carcinogens, the 3,4-quinone forms of the estrogens estrone (E1) and estradiol (E2). DNA was truncated to guanine, i.e. no deoxyribose moiety was included. Due to a complex reaction that involves proton transfer via water molecules we applied linear free energy relationships rather than computation of the transition state and activation energies. The minima corresponding to reactants and products were obtained on the B3LYP/6-31G(d) level. The effects of hydration were considered using the solvent reaction field of Tomasi and co-workers and the Langevin dipoles model of Florian and Warshel. No significant difference in reaction free energy for the reaction involving estrone and estradiol metabolites was found, despite the fact that for the two substances different carcinogenic activities were reported. Differences in carcinogenicity may be therefore attributed to other types of interactions or reactions such as (i) specific interactions of the carbonyl or hydroxyl group with DNA giving rise to different activation free energies for the reactions, (ii) the reaction of depurination and subsequent effects on the DNA, (iii) enzymatic or nonenzymatic oxidation steps (P450, aromatase, peroxidases, O2) and detoxification reactions (catechol-O-methyl transferase, S-transferase), or (iv) binding of the hormone to its nuclear receptors. 相似文献
87.
Copolymer network hydrogels were prepared by gamma irradiation of aqueous solutions of poly(vinyl pyrrolidone) (PVP) and acrylic acid monomer (AAc). The composition of the final hydrogels compared to the composition of the initial preparation solutions of hydrogels was determined. The chemical structure and nature of bonding was characterized by IR spectroscopy analysis, while the thermal durability of the prepared hydrogels was assessed by thermogravimetric analysis (TGA). The kinetic swelling in water and the pH-sensitivity of PVP/AAc copolymer hydrogels was studied. The drug release properties of PVP/AAc hydrogels taking methyl orange indicator as a drug model was investigated. The IR spectra indicate the formation of copolymer networks, whereas the TGA study showed that the PVP/AAc hydrogels possess higher thermal stability than pure PAAc and lower than PVP hydrogels. The kinetic swelling in water showed that all the hydrogels reached equilibrium after 24 h and that the degree of swelling increases with increasing the ratio of AAc in the initial feeding solutions. It was found that the degree of swelling of PVP/AAc hydrogels increases greatly within the pH range 4-7 depending on composition. 相似文献
88.
Summary A new method is described for the localization and estimation of sitosterols on a radiochromatogram. The method depends upon the addition of rado-iodine at the double bond of sitosterol on the developed paper chromatogram. It denotes the presence of - and -sitosterol in the two materials investigated with new Rf values in a new developing system.
Zusammenfassung Eine radiochemische Methode wird beschrieben zur Lokalisierung und Bestimmung von Sitosterinen auf Papierchromatogrammen. Das Verfahren beruht auf der Addition von radioaktivem Jod an die Doppelbindung des Sitosterols auf dem entwickelten Chromatogramm. In zwei untersuchten Substanzen konnten mit einem neuen Lösungsmittelsystem - und -Sitosterin nachgewiesen werden.相似文献
89.
90.
建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定人血清中孕酮的分析方法。血清样品经乙酸乙酯、正己烷液液萃取(LLE)后,采用Acquity UPLC BEH C_(18)色谱柱(2.1 mm×100 mm,1.7μm)进行梯度分离,色谱运行时间为5 min,采用电喷雾(ESI)正离子电离模式和多反应监测(MRM)扫描模式,同位素内标法定量。考察了两步萃取法对孕酮的提取效果,不同流动相的分离效果以及样品稳定性,结果表明以甲醇-0.1%氨水溶液为流动相时分离效果较好。优化条件下,孕酮在10~10 000pg/mL范围内线性关系良好(r~2=0.999 8),方法检出限和定量下限分别为5、10 pg/mL;平均加标回收率为91.5%~106%,日内相对标准偏差(RSD)为1.2%~8.2%,日间RSD为4.1%~9.1%。采用该方法对30个真实血清样品进行测定,孕酮质量浓度为0.050 2~1.363 5 ng/mL,均在正常生理范围内。该方法灵敏度高、准确可靠,可用于临床血清样品中孕酮生理水平的检测。 相似文献