Hydraulic Resistance and Capacitance in the Soil-Plant System

In this paper, the hydraulic resistances and capacitances were evaluated. based on the development of non-(?) model of water flow in the soil-plant system and the simulating experiment work.The results show that the mean hydraulic resistance in the soil-plant system is 6.79×109 MPa·S·m-3; the mean hydraulic capacitance in the system is 5.2×107m3·MPa-1. In the components of hydraulic capacitance in the system, the capacitance in soil (81.8×10-6m3·MPa ) is the biggest and its variability with suii water potential is extremely strong, the capacitance in plant (5.3×10-7m3·MPa-1) is much smaller than that in soil, and the capacitance in shoots (15.5×10-7m3·2MPa-1) is bigger than that in roots (8.4×10-7m3·2MPa-1). An interesting result is that the capacitance in plant is almost equivalent to that in the soil-plant system.

CFD Prediction of Mean Flow Field and Impeller Capacity for Pitched Blade Turbine

This work focused on exploring a computational fluid dynamics(CFD)method to predict the macromixing characteristics including the mean flow field and impeller capacity for a 45° down-pumping pitched blade turbine(PBT)in stirred tanks. Firstly, the three typical mean flow fields were investigated by virtue of three components of liquid velocity. Then the effects of impeller diameter(D)and off-bottom clearance(C)on both the mean flow field and three global macro-mixing parameters concerning impeller capacity were studied in detail. The changes of flow patterns with increasing C/D were predicted from these effects. The simulation results are consistent with the experimental results in published literature.

Cold acclimation induced accumulation of phenolic compounds and freezing tolerance in Ammopiptanthus mongolicus

Ammopiptanthus mongolicus, the only freezing tolerant evergreen broad-leaved shrub, local species of the Alashan desert, northwest sand area of China, can survive -30℃ or even lower temperature in winter. In the present study, the secondary products phenolics in A. mongolicus cotyledons were determined to study the effects of phenolics on cold tolerance. Cytochemical localization of phenolics in cotyledon cells was observed by electron microscopy and the content of phenolic compounds was assayed by spectrophotometric measurement. The results showed that the freezing tolerance ofA. mongolicus seedlings increased after acclimation at 2℃ for 14 days, which accompanied the increase of the content of phenolic compounds in cotyledons. Cytochemical observation showed that phenolic deposits were mainly localized in vacuoles and in close proximity to tonoplast, and also in the cytoplasm. The amount and the size of phenolics droplets increased obviously in cytoplasm and vacuoles after cold acclimation, predominantly aggregated along membranes of vacuoles and tonoplast. No phenolic deposits were found in cell walls. As hydrogen- or elec- tron-donating agents, phenolics may protect plant cells against reactive oxygen species formed during chilling or freezing stress and improve the freezing tolerance of cold-acclimated A. mongolicus seedlings.

Compatible taper and stem volume equations for Larix kaempferi(Japanese larch) species of South Korea

In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.

Asymptotically Optimal and Admissible Empirical Bayes Estimation of Normal Parameter

Under square loss, this paper constructs the empirical Bayes（EB） estimation for the parameter of normal distribution which has both asymptotic optimality and admissibility. Moreover, the convergence rate of the EB estimation obtained is proved to be O（n^-1）.

LSA Based Classification of Advertising Spam Reviews

In this study, methods to classify advertising reviews from shopping mall reviews are suggested. Advertising reviews are mostly written by companies and contain advertising contents. There are a few studies regarding the classification of opinion spam documents, which is very rare in foreign studies; however, there are no studies that classify advertising reviews from Korean reviews. In this study, the Naive Bayes Classifier was used to classify review documents and the POS （Part-of-Speech）-Tagging and bigram methods were used to extract specific words. The frequency calculation methods for the probability value of specific words were： （1） The general number of appearances of words （2） the frequency calculation of specific words through the suggested Latent Semantic Analysis （LSA）, and by recalculating the result from （1） in （2）, the performances of each method were compared. As a result, the methods from （2） showed 88.43% accuracy which is 8.89% higher than 79.54% which was the previous result from using the POS-Tagging ＋ Bigram method. Therefore, it was proved that the method suggested in this study is effective at classifying or extracting advertising reviews from Korean product review documents.

Comparison on Hemocompatibility of MWCNTs and Hydroxyl Modificated MWCNTs

Objective: To study and compare the hemocompatibility of MWCNTs and hydroxyl modificated MWCNTs (MWCNTs-OH). Methods: MWCNTs and MWCNTs-OH were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, water contact angle assays, platelet-adhesion and hemolytic rate assays. Results: The results showed that the two MWCNTs had a similar surface topography and MWCNTs-OH were functionalized with hydroxyl groups on their surfaces. Water contact angle assays indicated that MWCNTs were hydrophobic materials, whereas MWCNTs-OH was hydrophilic. The platelet-adhesion assays displayed that the platelet-adhesion rate of MWCNTs-OH was much lower than MWCNTs. The hemolytic rate assays showed that the hemolytic rates of both MWCNTs were lower than the standard value of 5%. Conclusion: MWCNTs-OH shows superior anticoagulant capacity over MWCNTs. Both MWCNTs and MWCNTs-OH are nonhemolytic materials.

Composition change and capacitance properties of ruthenium oxide thin film

Ru O2·n H2O film was deposited on tantalum foils by electrodeposition and heat treatment using Ru Cl3·3H2O as precursor.Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·n H2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2h, RuO2·n H2O electrode surface gains mass of2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly20% with voltage scan rate increasing from 5 to 250 m V/s.

船山先师诗录

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Influence of Humic Acid on Interaction of Ammonium and Potassium Ions on Clay Minerals

Interaction of ammonium (NH+4) and potassium (K+) is typical in field soils. However, the effects of organic matter on interaction of NH+4 and K+have not been thoroughly investigated. In this study, we examined the changes in major physicochemical properties of three clay minerals (kaolinite, illite, and montmorillonite) after humic acid (HA) coating and evaluated the influences of these changes on the interaction of NH+4 and K+on clay minerals using batch experiments. After HA coating, the cation exchange capacity (CEC) and specific surface area (SSA) of montmorillonite decreased significantly, while little decrease in CEC and SSA occurred in illite and only a slight increase in CEC was found in kaolinite. Humic acid coating significantly increased cation adsorption and preference for NH+4, and this effect was more obvious on clay minerals with a lower CEC. Results of Fourier transform infrared spectrometry analysis showed that HA coating promoted the formation of H-bonds between the adsorbed NH+4 and the organo-mineral complexes. HA coating increased cation fixation capacity on montmorillonite and kaolinite, but the opposite occurred on illite. In addition, HA coating increased the competitiveness of NH+4 on fixation sites. These results showed that HA coating affected both the nature of clay mineral surfaces and the reactions of NH+4 and K+with clay minerals, which might influence the availability of nutrient cations to plants in field soils amended with organic matter.

In situ forming chitosan-based hydrogel as a lung sealant for biological lung volume reduction

Biological lung volume reduction （BLVR） using lung sealant has received more attention recently as a new non-surgical approach to emphysema treatment. Many tissue sealants have been studied but only a few have been proposed for BLVR. In this work, we prepared in situ forming chitosan-based hydrogels （CSG） using covalent cross-linking of chitosan and genipin in the cooperation of ionic interaction between chitosan and sodium orthophosphate hydrate （Na3PO4.12H20） and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and rheological methods. CSG showed short gelation time （8 min）, high swelling ratio （〉100 %） and non-toxicity （3T3 mouse fibroblast cell viability 〉80 %） under physiological conditions. The application of lung sealant for BLVR was tested in a Chinese dog and evaluated by chest computed tomography. After 3 weeks of the installation of CSG in bronchopulmonary segment, the gel formation was detected at a localized region of bronchi and the local atelectasis occurred. Our findings indicate that this chitosan-based hydrogel is a promising new candidate for use as a lung sealant for BLVR.

Leaf hydraulic traits of larch and ash trees in response to long-term nitrogen addition in northeastern China

Aims Atmospheric nitrogen(N)deposition influences tree hydraulic architecture and thus the growth and survival;but the responses of leaf hydraulic traits remain uncertain,and may vary with species or plant functional types.Methods We used the 16-year N addition experiment(10 g N m−2 year−1)on Fraxinus mandshurica(ash,broadleaf angiosperm)and Larix gmelinii(larch,conifer gymnosperm)plantations in northeastern China and examined the effect of N addition on their leaf hydraulics.We measured the leaf pressure–volume traits by the bench drying method and quantified the maximum leaf hydraulic conductance(K_(leaf_max))and resistance to embolism(P50leaf)by the timed rehydration method.Important Findings Larch had higher K_(leaf_max)and stronger drought tolerance(i.e.,lower relative water content at turgor loss point(RWC_(tlp))and modulus of elasticity(ε),and more negative P50leaf)than ash.N addition increased the leaf osmotic potential at turgor loss(πtlp)and full turgor(π0),and leaf capacitance(Cleaf_mass)for ash but not for larch,indicating that ash is more sensitive to N addition.N addition consistently increased K_(leaf_max)and P50leaf values for both species.πtlp andπ0 were positively while Cleaf_mass was negatively correlated with leaf density(LD)for ash.K_(leaf_max)was positively but P50leaf was negatively related with LD for larch.There were negative relationships between K_(leaf_max)and P50leaf for both species.Overall,our findings suggest that long-term N addition decreases the leaf drought tolerance for these two important tree species,which improve the understanding of the tree hydraulic performance under N deposition.

Theoretical analysis of the harmonic characteristics of modular multilevel converters

To understand the operation principle of the modular multilevel converter(MMC)deeply,it is necessary to study the harmonic characteristics of the MMC theoretically.Besides,the analytical harmonic formulas of the MMC are useful in designing the main circuit,reducing the losses and improving the waveform quality.Based on the average switching function and the Fourier series harmonic analysis,this paper deduces the analytical expressions for such electrical quantities as the arm voltage,the arm current,the capacitor voltage,the capacitor current and the circulating current of the MMC.Finally,a digital model of a 21-level MMC-HVDC system is realized in PSCAD/EMTDC.The results of the analytical expressions coincide with the simulation results,which verify the effectiveness and feasibility of the proposed analytical expressions.