The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphrag...The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.展开更多
The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique...The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique at room temperature and atmosphere pressure. The influence of olefins on adsorptive desulfurization of model fuel had been investigated by FT-IR techniques, which revealed that the protons in the zeolites were the sites responsible for the adsorption of olefins. On the CeY zeolite, in the presence of strong hydroxyl species in the zeolites, the adsorbed olefin compounds can attach to the protons molecularly via electrophilic interaction and undergo the opening of the C=C bonds depending on the acidity of the zeolites. The reduced desulfurization performance of CeY zeolite was attributed to the direct occupation of the absorbent's active sites by olefins. In contrast to the CeY zeolite, the NiY zeolites were unable to react directly with pure olefins. However the sulfur compounds and olefins adsorbed on the protons may subsequently undergo olefin alkylation reactions, which can block the zeolite pores and then prevent sulfide molecules from having access to super-cages to contact with the metal cations. This work demonstrates also that the NiY zeolites exhibit excellent performance for selective adsorption desulfurization of model fuel containing olefin compounds.展开更多
To determine the degree of oxidation in vegetable oil, a photochemical method using the electron spin resonance (ESR) spin trapping technique was developed, and the results were compared with those obtained using co...To determine the degree of oxidation in vegetable oil, a photochemical method using the electron spin resonance (ESR) spin trapping technique was developed, and the results were compared with those obtained using conventional peroxide-value (PV) and acid-value (AV) methods. Vegetable oil heat-treated were subjected to short UV illumination, and the produced alkyl-oxyl radicals were identified and quantified using the ESR spin trapping technique. ESR signal intensity was used as an indicator of oil oxidation, which monotonically increased as a function of the heat-treatment time. Commercially, available oils were selected and analyzed. The results were compared with those obtained using the PV and AV methods. The present method displayed some analogies with the PV method at least in the early stage of heating. Overall, the present method had highly sensitive and capable of detecting early-stage oxidation in vegetable oil.展开更多
Damages of power transformers are caused partly by construction setting but also by operation (i. e., due to operational and degradation parameters). A long-term operation and exceeding of the limit values of transf...Damages of power transformers are caused partly by construction setting but also by operation (i. e., due to operational and degradation parameters). A long-term operation and exceeding of the limit values of transformer abbreviate the lifetime of this device very dramatically. A condition of insulating system oilpaper is principal diagnostic indicator that has its essential influence to failure-free operation of power transformers. The paper deals with a description of the experience with developed monitoring system, which is focused mainly on a control of oil filling of experimental transformer. Relative humidity, amount of dissolved gases and increased temperature are observed, as they have decisive influence on insulating system of transformer. Monitoring of these characteristics is completed with analysis of oil samples by infrared spectroscopy in mode of Attenuated Total Reflection technique.展开更多
Currently "The Crude Formulation Technique" developed by the SINOPEC Research Institute of Petroleum Processing(RIPP) has passed the technical review sponsored by the Sinopec Corp.This technique by means of adopti...Currently "The Crude Formulation Technique" developed by the SINOPEC Research Institute of Petroleum Processing(RIPP) has passed the technical review sponsored by the Sinopec Corp.This technique by means of adopting the advanced algorithm on the basis of the crude assay data bank and the large crude spectroscopic database can intelligently blend together different kinds of crude oils to obtain multiple crude formulations, the quality of which is quite close to the target crude in a bid to provide technical support to the refining enterprises in the area of crude procurement and sustained property stabilization of crude oils pro-cessed thereby.展开更多
Hyperspectral remote sensing makes it possible to non-destructively monitor leaf chlorophyll content (LCC). This study characterized the geometric patterns of the first derivative reflectance spectra in the red edge...Hyperspectral remote sensing makes it possible to non-destructively monitor leaf chlorophyll content (LCC). This study characterized the geometric patterns of the first derivative reflectance spectra in the red edge region of rapeseed (Brassica napus L.) and wheat (Triticum aestivum L.) crops. The ratio of the red edge area less than 718 nm to the entire red edge area was negatively correlated with LCC. This finding allowed the construction of a new red edge param- eter, defined as red edge symmetry (RES). Compared to the commonly used red edge parameters (red edge position, red edge amplitude, and red edge area), RES was a better predictor of LCC. Furthermore, RES was easily calculated using the reflectance of red edge boundary wavebands at 675 and 755 nm (R675 and R755) and reflectance of red edge center wavelength at 718 nm (R718), with the equation RES = (R71s - R675)/(R755 - R675). In addition, RES was simulated effectively with wide wavebands from the airborne hyperspectral sensor AVIRIS and satellite hyperspectral sensor Hyperion. The close relationships between the simulated RES and LCC indicated a high feasibility of estimating LCC with simulated RES from AVIRIS and Hyperion data. This made RES readily applicable to common airborne and satellite hyperspectral data derived from AVIRIS and Hyperion sources, as well as ground-based spectral reflectance data.展开更多
文摘The principle of miniature isolated solid-state encapsulation technology of high-temperature pressure sensor and the structure of packaging are discussed, including static electricity bonding, stainless steel diaphragm selection and rippled design, laser welding, silicon oil infilling, isolation and other techniques used in sensor packaging, which can affect the performance of the sensor. By adopting stainless steel diaphragm and high-temperature silicon oil as isolation materials, not only the encapsulation of the sensor is as small as 15 mm in diameter and under 1 mA drive, its full range output is 72 mV and zero stability is 0.48% F.S/mon, but also the reliability of the sensor is improved and its application is widely broadened.
基金supported by the National Natural Science Foundation of China(No. 20476042 and No.20776064)the Ministry of Science and Technology of the People's Republic of China under the National Basic Research Program of China(973 Program) (2007CB216403)
文摘The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique at room temperature and atmosphere pressure. The influence of olefins on adsorptive desulfurization of model fuel had been investigated by FT-IR techniques, which revealed that the protons in the zeolites were the sites responsible for the adsorption of olefins. On the CeY zeolite, in the presence of strong hydroxyl species in the zeolites, the adsorbed olefin compounds can attach to the protons molecularly via electrophilic interaction and undergo the opening of the C=C bonds depending on the acidity of the zeolites. The reduced desulfurization performance of CeY zeolite was attributed to the direct occupation of the absorbent's active sites by olefins. In contrast to the CeY zeolite, the NiY zeolites were unable to react directly with pure olefins. However the sulfur compounds and olefins adsorbed on the protons may subsequently undergo olefin alkylation reactions, which can block the zeolite pores and then prevent sulfide molecules from having access to super-cages to contact with the metal cations. This work demonstrates also that the NiY zeolites exhibit excellent performance for selective adsorption desulfurization of model fuel containing olefin compounds.
文摘To determine the degree of oxidation in vegetable oil, a photochemical method using the electron spin resonance (ESR) spin trapping technique was developed, and the results were compared with those obtained using conventional peroxide-value (PV) and acid-value (AV) methods. Vegetable oil heat-treated were subjected to short UV illumination, and the produced alkyl-oxyl radicals were identified and quantified using the ESR spin trapping technique. ESR signal intensity was used as an indicator of oil oxidation, which monotonically increased as a function of the heat-treatment time. Commercially, available oils were selected and analyzed. The results were compared with those obtained using the PV and AV methods. The present method displayed some analogies with the PV method at least in the early stage of heating. Overall, the present method had highly sensitive and capable of detecting early-stage oxidation in vegetable oil.
文摘Damages of power transformers are caused partly by construction setting but also by operation (i. e., due to operational and degradation parameters). A long-term operation and exceeding of the limit values of transformer abbreviate the lifetime of this device very dramatically. A condition of insulating system oilpaper is principal diagnostic indicator that has its essential influence to failure-free operation of power transformers. The paper deals with a description of the experience with developed monitoring system, which is focused mainly on a control of oil filling of experimental transformer. Relative humidity, amount of dissolved gases and increased temperature are observed, as they have decisive influence on insulating system of transformer. Monitoring of these characteristics is completed with analysis of oil samples by infrared spectroscopy in mode of Attenuated Total Reflection technique.
文摘Currently "The Crude Formulation Technique" developed by the SINOPEC Research Institute of Petroleum Processing(RIPP) has passed the technical review sponsored by the Sinopec Corp.This technique by means of adopting the advanced algorithm on the basis of the crude assay data bank and the large crude spectroscopic database can intelligently blend together different kinds of crude oils to obtain multiple crude formulations, the quality of which is quite close to the target crude in a bid to provide technical support to the refining enterprises in the area of crude procurement and sustained property stabilization of crude oils pro-cessed thereby.
基金Supported by the Program for New Century Excellent Talents in University of China(No.NCET-08-0797)the National Natural Science Foundation of China(No.30871448)+1 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK2008330)the Program for the Creative Scholars of Jiangsu Province,China(No.BK20081479)
文摘Hyperspectral remote sensing makes it possible to non-destructively monitor leaf chlorophyll content (LCC). This study characterized the geometric patterns of the first derivative reflectance spectra in the red edge region of rapeseed (Brassica napus L.) and wheat (Triticum aestivum L.) crops. The ratio of the red edge area less than 718 nm to the entire red edge area was negatively correlated with LCC. This finding allowed the construction of a new red edge param- eter, defined as red edge symmetry (RES). Compared to the commonly used red edge parameters (red edge position, red edge amplitude, and red edge area), RES was a better predictor of LCC. Furthermore, RES was easily calculated using the reflectance of red edge boundary wavebands at 675 and 755 nm (R675 and R755) and reflectance of red edge center wavelength at 718 nm (R718), with the equation RES = (R71s - R675)/(R755 - R675). In addition, RES was simulated effectively with wide wavebands from the airborne hyperspectral sensor AVIRIS and satellite hyperspectral sensor Hyperion. The close relationships between the simulated RES and LCC indicated a high feasibility of estimating LCC with simulated RES from AVIRIS and Hyperion data. This made RES readily applicable to common airborne and satellite hyperspectral data derived from AVIRIS and Hyperion sources, as well as ground-based spectral reflectance data.