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排序方式: 共有751条查询结果,搜索用时 531 毫秒
741.
The internally cooled coated fiber device was miniaturized to allow its direct introduction into a gas chromatography injector, while maintaining a reasonable lifetime of the septum. The device was robust, and its fiber, which was accommodated in an 18-gauge needle, was reproducibly used for more than 100 injections without any coating failure. The fiber temperature was controlled within 5 degrees C of the preset value by use of a temperature controller, a solenoid valve, and stainless steel tubings with different inner diameter. The device was mounted and used on the CTC CombiPAL autosampler with minor modifications, such as enlarging the hole of the needle guide of the autosampler and coupling the temperature control system of the device to the autosampler through a logic circuit. The device was validated with the back equilibration of hydrocarbons preloaded in the fiber in air. The automation of the internally cooled coated fiber device provided the feasibility of high throughput for the analysis of analytes in complex matrixes that required simultaneous heating of the sample matrixes and cooling of the fiber coating. 相似文献
742.
Volatile organic compounds (VOCs) are the major pollutants in indoor air, which significantly impact indoor air quality (IAQ). As a promising technique to remove VOCs, photocatalytic oxidation (PCO) takes the advantages of oxidation of a large range of VOCs with low energy consumption. In this study, the mass transports and reaction mechanism involved in the PCO process have been studied. In addition, the kinetic models of PCO on the different conditions of elementary reactions have been critically reviewed. Moreover, the factors that may affect the efficiency of PCO were interpreted based on the established fundamental mechanism of PCO. Some recommendations were made for future work to improve the efficiency of PCO system for building applications. 相似文献
743.
744.
Joanna?LeszczynskaEmail author Agata???cka Janusz?Szemraj Jolanta?Lukamowicz Henryk?Zegota 《European Food Research and Technology》2003,217(5):387-391
Commercial gliadins and wheat flour were exposed to microwaves at power distribution of 70, 200, and 500 W for different time periods to achieve a level of applied energy doses up to 150 kJ. Ethanolic extracts (40 vol.% ethanol/water) of microwave treated samples were analyzed by ELISA with the use of either monoclonal antibodies against -gliadin or polyclonal anti-gliadin antibodies and by electrophoresis followed by immunoblotting. A significant increase in reactivity, almost 210% over the untreated control sample, was observed for gliadins exposed to the energy dose of 40 kJ. Gliadins treated with higher energy doses showed a drop in an immune response independent of monoclonal or polyclonal antibodies used in ELISA. Gliadin fractions extracted from wheat flour treated with microwaves demonstrated similar immunoreactivity changes vs applied energy, although the maximum of reactivity appeared at 30 kJ. The increase in immune response of microwave irradiated gliadins was also confirmed by immunoblotting assay with the use of sera of patients susceptible to wheat flour allergy. Reversed phase HPLC elution profiles of treated gliadins showed that the content of all gliadin fractions in microwave treated samples decreased with the increase of the dose of applied energy. 相似文献
745.
The paper concerns the phenomena of the fluid film that occurs in the bearing chamber of an aircraft engine.The geometry of the system includes two concentric cylinders,between which there is a mixture of oil and air.The fluid circulates in a closed circuit.The rotary movement of the inner cylinder causes creation of the fluid film on the walls of the chamber.The article proposes a measurement method that is allowing observation of this fluid film and,in particular,analysis of the movement of the air bubbles occurring in the film.An own model of the bearing chamber with transparent walls was constructed for the research.For the investigation,water was used instead of oil.Observation of the behaviour of the flow was possible thanks to video recordings made with the use of a fast-capture camera.The results presented in the paper include velocity magnitudes of the air bubbles in the fluid film in dependence on the rotational speed of the shaft and water volume fraction and with a range from 0.37 to 0.91 m/s.The results presented in this article can be used for the bearing chamber numerical models validation. 相似文献
746.
This paper reports the interim results of an experimental project using neural networks as a decision support tool for credit card risk assessment within a major bank. Two prototype neural network systems have been developed: one which emulates the decisions of the current risk assessment system, and another which attempts to predict the performance of credit card accounts based on the accounts historical data. This paper focuses on the development of the neural network model for credit card account performance prediction. The study has shown that such a tool can help in discovering the potential problems with credit card applicants at the very early stage of the credit account life cycle. 相似文献
747.
Kluczyński Janusz Śnieżek Lucjan Grzelak Krzysztof Torzewski Janusz Szachogłuchowicz Ireneusz Wachowski Marcin 《Metallurgical and Materials Transactions A》2023,54(1):196-210
Metallurgical and Materials Transactions A - In this paper, the influence of the additive manufacturing (AM), powder bed fusion (PBF) process parameters on the low-cycle fatigue (LCF) properties of... 相似文献
748.
This paper concerns the problems of the parameter values estimation of d.c. electrothermal model of the BJT formulated for circuit analysis with SPICE. In this case, PARTS software available in SPICE cannot be used. In the paper, a new estimation algorithm for d.c. electrothermal model of the BJT is proposed. The form of the electrothermal BJT model is also presented. The estimation algorithm implemented into the computer‐controlled measurement set allows one to derive the values of the parameters automatically after the measurements of the selected isothermal characteristics and proper calculations. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
749.
Huang Chao-Wei Chen Rou-An Chen Wei-Yu Nguyen Van-Huy Lin Kun-Yi Andrew Lasek Janusz 《Topics in Catalysis》2023,66(1-4):34-40
Topics in Catalysis - Various ZnTiO3 perovskites replacing A and B sites by La, Zr dopants were successfully synthesized via the ultrasonic-assisted sol–gel method. Different calcination... 相似文献
750.
Pattern Analysis and Applications - The method of the learning of vague languages which represent distorted/ambiguous patterns is proposed in the paper. The goal of the method is to infer the... 相似文献