Both titanium and germanium were introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO 2 laser.It is indica...Both titanium and germanium were introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO 2 laser.It is indicated by IR absorption spectra that as the content of SiO 2 decreases in this glass system TiO 2 and GeO 2 tends to exist in their own phases.As for the gel glass with a composition of 40SiO 2·30TiO 2·30GeO 2,when the temperature is below 600℃,germanium atoms exist mainly in Ge-O-Ge bonds.With the temperature increasing from 800℃ to 1000℃, titanium atoms in Si-O-Ti bonds almost transform into Ti-O-Ti bonds.Furthermore,a large number of Si-O-Ti and Si-O-Ge bonds formed when the temperature approaches 800℃,which makes a notable IR absorption band round the wavelength of CO 2 laser.Therefore, sol-gel based SiO 2-TiO 2-GeO 2 gel glass is a candidate material for CO 2 laser hollow waveguide.展开更多
In order to precisely retrieve the atmospheric CO2 , a retrieval method based on both near infrared （NIR） and thermal infrared （TIR） is established firstly. Then a look-up-table （LUT） based fast line-by-line rad...In order to precisely retrieve the atmospheric CO2 , a retrieval method based on both near infrared （NIR） and thermal infrared （TIR） is established firstly. Then a look-up-table （LUT） based fast line-by-line radiative transfer model （RTM） was integrated into the retrieval procedure to accelerate radiative transfer calculations. The LUT stores gas absorption cross-sections as a function of temperature, pressure and wavenumber. It could greatly reduce calculating time in radiative transfer compared to direct line-by-line method. Then retrieval was simulated using NIR, TIR and both bands. The retrieved CO2 profiles suggest joint approach could reconstruct CO2 profile better than those using NIR or TIR alone. Joint retrieval using both bands simultaneously could provide better constrain to CO2 vertical distribution in the whole troposphere.展开更多
温室气体（CO2）过量排放可以导致全球气候变暖,而碳捕捉与储存（carbon capture and storage,CCS）技术是一种减少CO2气体排放的有效措施。但存储在地下的CO2有泄漏的风险,如何快速监测CO2轻微泄漏点是一个值得研究的问题。该文通过野...温室气体（CO2）过量排放可以导致全球气候变暖,而碳捕捉与储存（carbon capture and storage,CCS）技术是一种减少CO2气体排放的有效措施。但存储在地下的CO2有泄漏的风险,如何快速监测CO2轻微泄漏点是一个值得研究的问题。该文通过野外模拟实验,研究草地和大豆在CO2轻微泄漏胁迫下的冠层光谱特征,构建CO2轻微泄漏点高光谱遥感探测模型。在2008年5月—9月于英国诺丁汉大学Sutton Bonington校区（52.8N,1.2W）进行了野外模拟实验。实验共设置16个小区,8个草地及8个大豆地,其中各有4个小区进行CO2泄漏胁迫。冠层光谱采用美国ASD光谱仪进行测量,草地测量了6次数据,大豆地测量了3次数据。实验结果表明,草地与大豆地的冠层光谱反射率在580~680nm波段范围内随CO2泄漏胁迫程度的增大而增大,且在整个试验期内都保持同样的规律,因此构建面积指数AREA（580~680nm）（光谱曲线在580~680nm波段范围内包围的面积）识别遭受CO2泄漏胁迫下的植被。通过J-M距离检验,发现该指数能够较好地识别出CO2轻微泄漏胁迫下center区与core区的草地,但对edge区草地的识别能力不足（J-M距离小于1.8）;该指数可以可靠且稳健地识别出遭受CO2轻微泄漏胁迫的大豆。该研究结果可为未来应用高光谱遥感探测CO2轻微泄漏点提供理论依据与方法支持。展开更多
Formation characteristic of CO2 corrosion product layer on the surface of P110 steel was investigated in simulated oilfield environment using massqoss experiment, potentiodynamic polarization curve, impedance spectros...Formation characteristic of CO2 corrosion product layer on the surface of P110 steel was investigated in simulated oilfield environment using massqoss experiment, potentiodynamic polarization curve, impedance spectroscopy, and SEM micrograph analysis. Samples of different times up to 240 h were tested during exposure. Corrosion product was primarily composed of Fe（Ca, Mg）（CO3 ）2, which was distinguished by two layers. With an increase in the exposure time, the charge transfer resistance and polarization resistance increased progressively, the uniform cor- rosion rate decreased, and the corrosion reaction was controlled by the diffusion process instead of the activation process. All phenomena were attributed to the formation of the protective corrosion product layer. More compact and lower porosity of the layer made it more difficult to transfer and diffuse through the corrosion product layer for the charges and ions. Similar results were obtained bv electrochemical test and mass-loss experiment.展开更多
文摘Both titanium and germanium were introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO 2 laser.It is indicated by IR absorption spectra that as the content of SiO 2 decreases in this glass system TiO 2 and GeO 2 tends to exist in their own phases.As for the gel glass with a composition of 40SiO 2·30TiO 2·30GeO 2,when the temperature is below 600℃,germanium atoms exist mainly in Ge-O-Ge bonds.With the temperature increasing from 800℃ to 1000℃, titanium atoms in Si-O-Ti bonds almost transform into Ti-O-Ti bonds.Furthermore,a large number of Si-O-Ti and Si-O-Ge bonds formed when the temperature approaches 800℃,which makes a notable IR absorption band round the wavelength of CO 2 laser.Therefore, sol-gel based SiO 2-TiO 2-GeO 2 gel glass is a candidate material for CO 2 laser hollow waveguide.
基金Supported by the National Natural Science Foundation of China(41175037)
文摘In order to precisely retrieve the atmospheric CO2 , a retrieval method based on both near infrared （NIR） and thermal infrared （TIR） is established firstly. Then a look-up-table （LUT） based fast line-by-line radiative transfer model （RTM） was integrated into the retrieval procedure to accelerate radiative transfer calculations. The LUT stores gas absorption cross-sections as a function of temperature, pressure and wavenumber. It could greatly reduce calculating time in radiative transfer compared to direct line-by-line method. Then retrieval was simulated using NIR, TIR and both bands. The retrieved CO2 profiles suggest joint approach could reconstruct CO2 profile better than those using NIR or TIR alone. Joint retrieval using both bands simultaneously could provide better constrain to CO2 vertical distribution in the whole troposphere.
文摘温室气体（CO2）过量排放可以导致全球气候变暖,而碳捕捉与储存（carbon capture and storage,CCS）技术是一种减少CO2气体排放的有效措施。但存储在地下的CO2有泄漏的风险,如何快速监测CO2轻微泄漏点是一个值得研究的问题。该文通过野外模拟实验,研究草地和大豆在CO2轻微泄漏胁迫下的冠层光谱特征,构建CO2轻微泄漏点高光谱遥感探测模型。在2008年5月—9月于英国诺丁汉大学Sutton Bonington校区（52.8N,1.2W）进行了野外模拟实验。实验共设置16个小区,8个草地及8个大豆地,其中各有4个小区进行CO2泄漏胁迫。冠层光谱采用美国ASD光谱仪进行测量,草地测量了6次数据,大豆地测量了3次数据。实验结果表明,草地与大豆地的冠层光谱反射率在580~680nm波段范围内随CO2泄漏胁迫程度的增大而增大,且在整个试验期内都保持同样的规律,因此构建面积指数AREA（580~680nm）（光谱曲线在580~680nm波段范围内包围的面积）识别遭受CO2泄漏胁迫下的植被。通过J-M距离检验,发现该指数能够较好地识别出CO2轻微泄漏胁迫下center区与core区的草地,但对edge区草地的识别能力不足（J-M距离小于1.8）;该指数可以可靠且稳健地识别出遭受CO2轻微泄漏胁迫的大豆。该研究结果可为未来应用高光谱遥感探测CO2轻微泄漏点提供理论依据与方法支持。
基金Item Sponsored by Program for New Century Excellent Talents in University of the Ministry of Education of China(NCET-07-0686)
文摘Formation characteristic of CO2 corrosion product layer on the surface of P110 steel was investigated in simulated oilfield environment using massqoss experiment, potentiodynamic polarization curve, impedance spectroscopy, and SEM micrograph analysis. Samples of different times up to 240 h were tested during exposure. Corrosion product was primarily composed of Fe（Ca, Mg）（CO3 ）2, which was distinguished by two layers. With an increase in the exposure time, the charge transfer resistance and polarization resistance increased progressively, the uniform cor- rosion rate decreased, and the corrosion reaction was controlled by the diffusion process instead of the activation process. All phenomena were attributed to the formation of the protective corrosion product layer. More compact and lower porosity of the layer made it more difficult to transfer and diffuse through the corrosion product layer for the charges and ions. Similar results were obtained bv electrochemical test and mass-loss experiment.
