Estimation of daily evapotranspiration in Northern China Plain by using MODIS/TERRA images

Evapotranspiration (ET) in regional scale is not only a major component of energy and water balance, but also a linking medium between ecological system and climatic system. Due to the increased needs from hydrological, climatological and ecological communities, more interest has been paid on developing algorithms to estimate ET over larger scales by means of combining remote sensing measurements of land surface parameters during the last decades. Compared to all previous remote sensing algorithms for heat fluxes estimations, the Surface Energy Balance System (SEBS) developed by Su (2002) has the most important advantage of its inclusion of a physical model for the estimation of the roughness height for heat transfer which is the most critical parameter in the parameterization of heat fluxes of land surface. In this paper, first, SEBS has been utilized to estimate the surface fluxes over HuangHuaiHai Plain in Northern China by using MODIS/TERRA images, in combination of meteorological data collected in meteorological stations distributed over the study area. The estimated fluxes by SEBS in clouds free days are first compared with the measurements from QRSLSP/Shunyi Campaign near Beijing (Liu et al.2002) and then compared to the measurements by Large Aperture Scintillometers (LAS) in Zhengzhou LAS station located in Henan Province, China. Both the comparisons show that the estimated fluxes from SEBS have a good agreement with the measurements. Based on the validation of the model, an extended modular of SEBS has been utilized to estimate daily ET over the study area and the results showed that the extended SEBS can be used to estimate daily ET over regional scale. Finally, limitations and special care in using SEBS are discussed

Beam Control in an Intracavity Frequency-Doubling Semiconductor Disk Laser

In this paper, we have demonstrated a 1.3 W green laser using a V-shaped intracavity frequency doubling 1036 nm semiconductor disk laser. The beam quality of the fundamental and second harmonic generation (SHG) laser is investigated. It has been found that the output lasers at the fundamental and SHG wavelength both suffer from reduced beam quality along with power scaling. The measured beam profile is elliptical under high power operation. In order to improve the SHG laser beam, an intracavity aperture is employed to control the mode characteristics of fundamental frequency light. By fine-tuning the aperture, a nearly circular beam profile with improving beam quality and brightness is realized

Biomass chemical-looping gasification coupled with water/CO2-splitting using NiFe2O4 as an oxygen carrier

Bio-syngas generation with flexible H-2 to CO ratios via biomass chemical-looping gasification (CLG) coupled with water/CO2-splitting using NiFe2O4 as an oxygen carrier (OC) was proposed in the present work. The presence of NiFe2O4 OC promotes biomass conversion, especially bio-char conversion at elevated temperature stage. Addition steam and/or CO2 into the carrying gas increased the weight loss rates of biomass. Up to 5.88 wt%/min and 4.97 wt%/min of the maximum weight loss rates were achieved during biomass conversion with NiFe2O4 OC in CO2 and steam flows in a TGA reactor, respectively. With NiFe2O4 as an oxygen carrier, an optimal lattice oxygen/biomass mass ratio is 0.51 giving the highest syngas yield of 0.77 m(3)/kg(b)(iomass) ass in the absence of steam or CO2 at 850 degrees C. Steam/biomass mass ratio of 2.25 gave the maximum carbon conversion of 92.53% and syngas yield of 1.38 m(3)/kg(b)(iomass) suggesting that steam addition significantly improves the biomass conversion and the syngas yield. Introducing a fraction of CO2 into steam could reduce the steam consumption as well as enhance the carbon conversion in biomass gasification step. NiFe2O4 OC serves as an effective catalyst for tars cracking in biomass-CLG. The tars content in the syngas generated in biomass-CLG with NiFe2O4 is 2.83 g/m(3), which is much lower than that (14.25 g/m(3)) in biomass gasification with inert ZrO2. The productivities of Hy and CO are 211 ml/g(OC )and 101 ml/g(OC) in water- and CO2-splitting steps. The proposed approach can potentially be applied for providing bio-syngas with flexible H-2 to CO ratios from 1:1 to 2.2:1 for purpose of various synthesis processes such as Fischer-Tropsch, acetic acid, and oxo-synthesis

Multifunctional Anticancer Platform for Multimodal Imaging and Visible Light Driven Photodynamic/Photothermal Therapy

As a potential photosensitizer for photodynamic therapy (PDT), pure titanium dioxide has the drawbacks of low tissue penetration and possible damage to skin due to the triggered UV light. To realize near-infrared (NIR) laser-induced multimodal imaging guided therapy, we constructed a multifunctional core–shell structure (TiO₂@Y₂Ti₂O₇@YOF:Yb,Tm) by a facile coprecipitation route, followed by an annealing process. Under a single NIR laser irradiation, the highly cytotoxic reactive oxygen species (ROS) required for PDT can be generated due to the energy transfer from YOF:Yb,Tm to the Y₂Ti₂O₇ photocatalyst which is responsive to blue emission (visible light), and the thermal effect can be simultaneously produced due to the nonradiative transition and the recombination of electron–hole pairs. The NIR light induced PDT and photothermal therapy (PTT) can efficiently suppress tumor growth, which was evidenced by both <i>in vitro</i> and <i>in vivo</i> results. Moreover, the rare earth ions in the composite make the material have good up-conversion luminescence (UCL) imaging and CT imaging properties, thus achieving the target of synergistic PDT and PTT therapy under the multimodal imaging guidance