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121.
122.
介绍了Robatech公司开发的PFC喷嘴。这种喷嘴为标准化组件,具有较大的适用性,既适用于新厂配套,也适用于老设备改造。 相似文献
123.
采用自行开发研制的超音速电弧喷设备,在45钢表面制成了钛铝合金复合涂层。并利用金相显微镜、X射线衍射仪、扫描电镜、电子探针,对涂层的成分、相结构、显微组织及其结合强度、显微硬度进行了研究。结果表明,利用超音速电弧喷涂设备,可以在45钢表面形成 度高、孔隙率低,结合强度较好和硬度高的Ti-Al合金涂层。 相似文献
124.
The kinetics of changes in the bound water content in dietetic sucrose-free sponge cakes (DC) during storage was investigated. The effect of edible films of polymyxan, pectin, xanthan, and carboxymethylcellulose upon this kinetics was also investigated. The quantitative changes in both states of water (slightly bound water and strongly bound water) were registered by combined dynamic analysis (thermogravimetry analysis, TGA, and differential thermal analysis, DTA). The moisture changes in DC crumb were analyzed by drying out to constant mass. The rate constants were determined according the equation q = qoe-kt. The values of rate constants 'k', in day-1, concerning the different edible films were as follows: for crumb moisture is (8.00 ≤ k ≤ 12.47) × 10-3, for bound water is (3.07 ≤ kw ≤ 6.26) × 10-2, for slightly bound water is (4.22 ≤ k1 ≤ 8.49) × 10-2 and for strongly bound water is (2.02 ≤ k2 ≤ 5.62) × 10-2 as compared to 18.53 × 10-3, 7.16 × 10-2, 9.04 × 10-2, and 5.36 × 10-2 in the uncovered DC, respectively. The best water-retaining effect in respect to crumb moisture during storage was ascertained in the use of polymyxan and xanthan films. The lowest rate constant values for bound water and its two states were measured for DC covered with pectin. The relation between the kinetics of both bound water states during storage and ageing of the crumb of DC covered with different edible films and the crumb microstructure was represented. By means of scanning electron microscope was read the smallest change in crumb microstructure of pectin-covered DC on the sixth day of storage. 相似文献
125.
Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts and similar equipments that are permanently or occasionally exposed to elevated temperatures. High-temperature coatings are generally based on silicone resin with ceramic and metallic pigments. In this study, iron oxide, cobalt oxide (thermo chromic compound) and aluminum oxide are used for the preparation of four new types of coloured pigments. The thermal resistant characteristics of these ceramic pigments were studied by differential thermal analysis, thermo gravimetric analysis and differential scanning calorimetric analysis. These ceramic pigments are found to be thermally stable up to 400 °C. 相似文献
126.
A series of new alternating aromatic poly(ester‐imide)s were prepared by the polycondensation of the preformed imide ring‐containing diacids, 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl (2a) and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl (2b) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A model compound (3) was also prepared by the reaction of 2b with phenol, its synthesis permitting an optimization of polymerization conditions. Poly(ester‐imides) were fully characterized by FTIR, UV‐vis and NMR spectroscopy. Both biphenylene‐ and binaphthylene‐based poly(ester‐imide)s exhibited excellent solubility in common organic solvents such as tetrahydrofuran, m‐cresol, pyridine and dichloromethane. However, binaphthylene‐based poly(ester‐imide)s were more soluble than those of biphenylene‐based polymers in highly polar organic solvents, including N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide and dimethyl sulfoxide. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 261 and 315 °C. Thermal behaviour of the polymers obtained was characterized by thermogravimetric analysis, and the 10 % weight loss temperatures of the poly(ester‐imide)s was in the range 449–491 °C in nitrogen. Furthermore, crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resultant poly(ester‐imide)s exhibited nearly an amorphous nature, except poly(ester‐imide)s derived from hydroquinone and 4,4′‐dihydroxybiphenyl. In general, polymers containing binaphthyl units showed higher thermal stability but lower crystallinity than polymers containing biphenyl units. Copyright © 2005 Society of Chemical Industry 相似文献
127.
A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl3, the influence of corrosive performance of CeCl3 on LC4 super-power aluminum alloy in the 0.1 mol·L−1 NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl3 solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al. 相似文献
128.
The effects of the uncertainties associated ith the apparent strain and gauge factor data, given by the manufacturer, in the evaluation of principal strains are examined. Principal strains are obtained by a reduction of the strains measured ith electrical resistance strain gauge rectangular or delta rosettes. The theoretical analysis points out the relevance of the effects caused. 相似文献
129.
K. O. Boltar I. D. Burlakov A. M. Filachev E. A. Klimanov V. P. Ponomarenko V. N. Solyakov V. I. Stafeev 《Optical Memory & Neural Networks》2007,16(4):234-247
The recent researches and technological developments of middle and long wavelength infrared HgCdTe photovoltaic detectors
are presented. Structure, topology, design and performance of HgCdTe photodiodes, silicon readout electronics, Focal Plane
Arrays both staring and time delay and integration types, thermal imagers are discussed. Negative differential conductance,
bistability and high frequency oscillations under background infrared radiation in HgCdTe photodiodes are reported. 相似文献
130.
A self-assembled monolayer (SAM) of p-hydroxymethylbenzene HOCH2C6H4 - (HOMB) moiety adsorbed on iron by the formation of a covalent bond between carbon and iron atoms was prepared by electrochemical derivatization of an iron electrode with p-hydroxymethylbenzenediazonium tetrafluoroborate HOCH2C6H4N2BF4. The electrode covered with the HOMB SAM was modified with alkyltriethoxysilanes CnH2n+1Si(OC2H5)3 (CnTES, n = 8 or 18) to prepare a film of one-dimensional polymer. The protective ability of the polymer film was determined by polarization measurement of the covered electrode in an aerated 0.5 M NaCl solution. The ability was enhanced by modification of the HOMB SAM with CnTES markedly. The iron surface coated with the one-dimensional polymer film of the HOMB SAM modified with C8TES was characterized by contact angle measurement and FTIR reflection and X-ray photoelectron spectroscopies. The persistence in the protective ability of the polymer film against iron corrosion in 0.5 M NaCl may be associated with the strong adsorption via the covalent bond, revealed by electron-probe microanalysis. 相似文献