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Relative pollen productivity (RPP) is the ratio of the absolute pollen productivity of a certain pollen taxon to the pollen reference taxon. It is an important parameter that can be used for quantitative reconstruction of paleovegetation at a landscape scale. Here we report a study on the estimation of the RPPs of five common pollen types of grassland vegetation from forest steppe, typical steppe and desert steppe in Hulunbuir, Xilinhot and Sonid Left Banner of Inner Mongolia. We used a 1 m×1 m quadrat to record plant species, rooted frequency and percentage cover at upwind to downwind direction at 0, 1, 2, 3.5, 5.5, 7.5, 9.5, 14.5 and 19.5 m distance from the trap. For the sites of 20–100 m distance from the trap, we investigated vegetation composition of the 1 m × 1 m quadrat with a 10-m interval. In the three study areas, Artemisia , Compositae, Gramineae, Chenopodiaceae and Cyperaceae were dominant plants. In the Hulunbuir forest steppe, Artemisia and Gramineae had the highest percentage. In the Xilinhot with typical steppe and the Sonid Left Banner with desert steppe, the percentage of Gramineae was the highest. We collected the pollen samples using modified Tauber traps from 2007 to 2013. The percentage of Chenopodiaceae in the Hulunbuir forest steppe was the lowest, but reached the highest in the Sonid Left Banner desert steppe, in contrast to those of Compositae, Gramineae and Cyperaceae. Our results show that the fall speed ( v g) varies among the five pollen types with 0.032 m/s for Gramineae, 0.027 m/s for Cyperaceae and Chenopodiaceae, 0.021 m/s for Artemisia and 0.019 m/s for Compositae. The RPPChe. was found the highest and RPPGra. the lowest in the three areas. When we used Artemisia as a reference taxon, the RPPs of the same pollen type are different in the three areas. For example, in the Hulunbuir forest steppe, the RPP Art . was 1.00, RPPCom. was 0.33, RPPGra. was 0.44, RPPChe. was 4.78 and RPPCyp. was 1.21. However, in the Xilinhot typical steppe, RPP Art. became 1.00, RPPCom. 4.72, RPPGra. 0.01, RPPChe. 2.05 and RPPCyp. 1.31×10 - 4; in the Sonid Left Banner desert steppe, RPP Art . was 1.00, RPPCom. 6.72, RPPGra. 2.15, RPPChe. 36.25 and RPPCyp. 0.41 respectively. The main reasons for the RPP differences might be the species dissimilarity in diverse vegetation types and the number of the sampling sites used in the models. The estimated relevant source areas of pollens (RSAPs) in all the three areas were less than 20 m. The coverage of different plants was reconstructed by the REVEALS model and presented a large difference among the three areas. In the Hulunbuir forest steppe, the Artemisia ’s coverage was 29.16%, Compositae18.66%, Gramineae 39.40%, Chenopodiaceae 3.53% and Cyperaceae 9.25%. In the Xilinhot typical steppe, the coverage of Artemisia reached 13.42%, Compositae 0.12%, Gramineae 61.69%, Chenopodiaceae 17.59% and Cyperaceae 7.17%. And in the Sonid Left Banner desert steppe, Artemisia reached a coverarge of 93.81%, Compositae 0.59%, Gramineae 1.22%, Chenopodiaceae 3.13% and Cyperaceae 1.25%. Compared with the actual vegetation coverage, the reconstructed coverage of Artemisia and Chenopodiaceae are higher, while that of Gramineae is far lower, which might be caused by the high background value of Artemisia .

This article reviews the developments of 4-thiothymidine analogues, assisted with UVA light, as a novel cancer therapy. First, the key points on synthetic chemistry, photochemistry and cellular toxicity of 4-thiothymidine are summarized. As the chemical structure of 4-thiothymidine is very similar to that of its parent thymidine, thus 4-thiothymidine can be readily incorporated into cellular DNA, and with the help of thymidine kinase, much more preferably into cancerous DNA. Unlike thymidine, 4-thiothymdine can absorb strongly in UVA (longer wavelengths of UV) light. Thus UVA-assisted 4-thiothymidine offers an effective cancer treatment. Some underlying mechanisms of action by 4-thiothymidine/UVA and compares this cancer approach with the commonly used photodynamic therapy are discussed. The various interactions between 4-thiothymidine with human serum albumin are introduced. Finally, a short conclusion on the past efforts and a brief prospect for future work in this exciting research field are given.

A novel anti-tumor agent 4-thio-5-(2′′-thienyl)uridine (6) was synthesized and the in vitro cytotoxicity activity against mice colon cancer cells (MC-38) and human colon cancer cells (HT-29) was evaluated by MTT assay. The results showed that the novel compound had antiproliferative activity toward MC-38 and HT-29 cells in a dose-dependent manner. The cell cycle analysis by flow cytometry indicated that compound 6 exerted in tumor cell proliferation inhibition by arresting HT-29 cells in the G2/M phase. In addition, cell death detected by propidium iodide staining showed that compound 6 efficiently induced cell apoptosis in a concentration-dependent manner. Moreover, the sensitivity of human fibroblast cells to compound 6 was far lower than that of tumor cells, suggesting the specific anti-tumor effect of 4-thio-5-(2′′-thienyl)uridine. Taken together, novel compound 6 effectively inhibits colon cancer cell proliferation, and hence would have potential value in clinical application as an antitumor agent.

In this paper, a new type of W band circular waveguide Y-junction circulator is presented. The structure of this type of Y-junction is a cylindrical cavity connecting with three circular waveguides. The performances of the type of circulator are analyzed by the edge-based vector finite element method hybridized with the modal expansion. The numerical results show that this type of waveguide Y junction circulator has good circulation performance.

A rectangular to circular groove waveguide transition is described in millimeter-wave band. The transition maintains a constant cutoff wavelength. Using the Finite Element Method, the size of the variable cross-section throughout the transition are calculated and the transition is designed.

International audience; The intermediate block is a basic element in an hydraulic control system, and is usually used to install all hydraulic components and guides the fluid flows. However, the effect of this block is usually neglected, but it has to be taken into consideration when high performance applications, especially at high frequencies, have to be achieved. This paper focuses on this component and shows how it can influence the hydraulic system dynamics. The main contributions of this work are the implementation of a Bond Graph model of this component, which can easily be integrated in the whole system model, and a complete analysis of the effects (pressure drop, compressibility, inertia) induced by the intermediate block on the whole system performances. The relationship between flow rates and pressure drops along with the energy losses in the block are obtained according to a method based on the decomposition of the circuit in parts for which the local losses can be obtained from abacuses. The Computational Fluid Dynamics (CFD) is used for the validation of the results. Besides, the compressibility and inertial effects are carefully studied since they have a great influence on the hydraulic frequency. Finally, simulations and experiments are implemented for demonstrating the importance of the effect of the intermediate block in the hydraulic system modeling. By introducing compressibility and inertial effects of the intermediate block, the simulation result shows better agreement with experimental results at high frequencies. This comparison demonstrates that the control design can reach better performance when considering the dynamic model of the intermediate block.

International audience; The intermediate block, as a basic element in the hydraulic control system, is used to install all hydraulic components and guides the fluid flows. The effect of this block, usually neglected, is taken into consideration in this paper since it is a part of a system developed for high performance applications and especially high frequencies [7]. By means of the Bond Graph tool, a detailed model is established. This model could then be easily integrated into the Bond Graph model of the whole system. Besides, the relationship between flow rates and pressure drops along with the energy losses in the block are obtained according to a method based on the decomposition of the circuit in parts for which the local losses can be obtained from abacuses. The computational fluid dynamics (CFD) is used for the validation of the results.

This paper presents a mobile 3D coordinate measuring system for large scale metrology. This system is composed of a network of rotating laser automatic theodolites (N-RLATs) and a portable touch probe. In the N-RLAT system, each RLAT consists of two laser fans which rotate about its own Z axis at a constant speed and scan the whole metrology space. The optical sensors mounted on the portable touch probe receive the sweeping laser fans and generate the corresponding pulse signals, which establish a relationship between rotating angle of laser fan and time, and then the space angle measurement is converted into the corresponding peak time precision measurement of pulse signal. The rotating laser fans are modeled mathematically as a time varying parametrical vector in its local framework. A two steps on-site calibration method for solving the parameters of each RLAT and coordinate transformation among the N-RLATs. The portable probe is composed of optical sensors array with specified geometrical features and a touch point, on which the coordinates of optical sensors is determined by the N-RLATs and the touch point is estimated by solving a non-linear system. A prototype mobile 3D coordinate measuring system is developed and experiment results show its validity.

This paper presents a new 3D positioning method of setting up a network of rotating laser automatic theodolites (RLAT) for the large scale metrology. In this system, each RLAT consists of two laser fans rotating about its own Z axis at constant speed and an optical sensor is used to detect the pulse signals of sweeping laser fans. Instead of estimating indirectly the two space angle of laser fans, the rotating laser fan is modelled as a time varying parametrical vector, which establish a new relationship between rotating angle of laser fan and time when laser fan sweeps over 3D point. Based on that, the network of RLATS is mathematically modelled as a non-linear equation system and a union calibration method is proposed to estimate the parametrical vectors of each RLAT and all transformation among network of RLATS by solving non-linear objective function optimally. A prototype network of RLATS is developed and experiment results show the validity of positioning 3D location in a large scale.

International audience; Bond Graph, as a graphical modeling language, can represent various physical domains in a unified form. This paper deals with the establishment of a Bond Graph model of an electro-hydraulic servovalve which consists of a torque motor, a cantilever feedback spring, and two hydraulic stages, one with a nozzle/flapper system and the other with a spool valve. The entire model can be divided into a hydraulic and a mechanical part which are connected by 2-port modulated R-elements representing orifice pressure drop and jet force phenomena, and TF-elements coupling the mechanical and hydraulic power. The Bond Graph model of whole system is then presented. Finally, using AMESim on which a model was created based on the established Bond Graph, simulation results are compared with the experimental measurements.

A novel method for analyzing generalized M-phase mains or force-commutated AC-DC converter circuits is described. The method utilizes the switched-function modulation lemma. As a result, the computation process of AC voltage and current as well as DC voltage and current is systematized. The harmonic contents of these variables are obtained in the closed form. One of the main features of this method of harmonic spectral analysis is the saving in computational time achieved when the harmonic spectral analysis is all that is required. This is because the program separates the calculation of harmonic spectral response from the calculation of the time-domain response. Numerical examples are included to illustrate the technique. >

This paper describes the analysis of the steady-state performance of a three phase six pulse thyristor controlled converter feeding a dc back emf load in series with a resistance and a smoothing dc link inductance. A complete current and voltage solution for the balanced three phase converter system is derived together with the harmonic spectrum analysis for both voltage and current on both dc and ac side. A novel method is used in deriving the complete results. The method utilizes the symmetrical property of three-phase ac supply systems in saving computing time by a factor of m which is the pulse number of the converter. Digital computer programs are developed to simulate the steady state performance of such a system. The losses and forward voltage drops of the conducting thyristors are taken into consideration by employing a first order thyristor model. The proposed method can be extended to the analysis of a more generalized system which considers ac system imbalances both in structure and in supply voltages and takes the filters both on dc and ac side into account.