Tectonic Implications of the Combined Use of Tectonomagmatic Geochemical Discrimination Diagrams and Indicators of Magma Flow Sense in Mafic Dykes

Geochemistry is a powerful tool to help characterize the tectonic setting of igneous rocks associations.However,when continental mafic dykes and flood basalts are the target most of the proposed geochemical discrimination diagrams fail to correctly classify them,i.e.many mafic

Uncertainty Quantification of Numerical Simulation of Flows around a Cylinder Using Non-intrusive Polynomial Chaos

The uncertainty quantification of flows around a cylinder is studied by the non-intrusive polynomial chaos method. Based on the validation with benchmark results, discussions are mainly focused on the statistic properties of the peak lift and drag coefficients and base pressure drop over the cylinder with the uncertainties of viscosity coefficient and inflow boundary velocity. As for the numerical results of flows around a cylinder, influence of the inflow boundary velocity uncertainty is larger than that of viscosity. The results indeed demonstrate that a five-order degree of polynomial chaos expansion is enough to represent the solution of flow in this study.

Subsurface Flow Processes in Sloping Cropland of Purple Soil

Subsurface flow is a prominent runoff process in sloping lands of purple soil in the upper Yangtze River basin.However,it remains difficult to identify and quantify.In this study,in situ runoff experimental plots were used to measure soil moisture dynamics using an array of time domain reflectometry(TDR) together with overland flow and subsurface flow using isolated collecting troughs.Frequency of preferential flow during rainfall events and the controls of subsurface flow processes were investigated through combined analysis of soil properties,topography,rainfall intensity,initial wetness,and tillage.Results showed that subsurface flow was ubiquitous in purple soil profiles due to welldeveloped macropores,especially in surface soils while frequency of preferential flow occurrence was very low(only 2 cases in plot C) during all 22 rainfall events.Dry antecedent moisture conditions promoted the occurrence of preferential flow.However,consecutive real-time monitoring of soil moisture at different depths and various slope positions implied the possible occurrence of multiple subsurface lateral flows during intensive storms.Rainfall intensity,tillage operation,and soil properties were recognized as main controls of subsurface flow in the study area,which allows the optimization of management practices for alleviating adverse environmental effects of subsurface flow in the region.

Time lag characteristics of sap flow in seed-maize and their implications for modeling transpiration in an arid region of Northwest China

Plant capacity for water storage leads to time lags between basal stem sap flow and transpiration in various woody plants. Internal water storage depends on the sizes of woody plants. However, the changes and its influencing factors in time lags of basal stem flow during the development of herbaceous plants including crops remain unclear. A field experiment was conducted in an arid region of Northwest China to examine the time lag characteristics of sap flow in seed-maize and to calibrate the transpiration modeling. Cross-correlation analysis was used to estimate the time lags between stem sap flow and meteorological driving factors including solar radiation（R_s） and vapor pressure deficit of the air（VPD_（air））. Results indicate that the changes in seed-maize stem sap flow consistently lagged behind the changes in R_s and preceded the changes in VPD_（air） both on hourly and daily scales, suggesting that light-mediated stomatal closures drove sap flow responses. The time lag in the maize＇s sap flow differed significantly during different growth stages and the difference was potentially due to developmental changes in capacitance tissue and/or xylem during ontogenesis. The time lags between stem sap flow and R_s in both female plants and male plants corresponded to plant use of stored water and were independent of total plant water use. Time lags of sap flow were always longer in male plants than in female plants. Theoretically, dry soil may decrease the speed by which sap flow adjusts ahead of shifts in VPD_（air） in comparison with wet soil and also increase the speed by which sap flow adjusts to R_s. However, sap flow lags that were associated with R_s before irrigation and after irrigation in female plants did not shift. Time series analysis method provided better results for simulating seed-maize sap flow with advantages of allowing for fewer variables to be included. This approach would be helpful in improving the accuracy of estimation for canopy transpiration and conductance using meteorological measurements.

NUMERICAL SIMULATION OF THE FLOW PAST WING-BODY USING EULER EQUATIONS

AbstractThis paper gives H-O type grid generation and applies finite-volume method forwing-body flow.A 3-D Euler code for wing-body has been developed. We improve in thiscode the distribution of the number of grid points over wing and body surfaces,and keepthe training edge of the wing being one of the grid lines even when the edge has sweepbackor sweep forward.The code developed can provide not only the spanwise pressure distribu-tion as usual ou cross-flow planes,but also the chordwise Pressure distributions.The com-putation for NASA TN D-712 wing-body model with the present code shows that thecomputed pressure distributions are in very good agreement with the experiment.

RECONSTRUCTION OF PART OF AN ACTUAL BLAST-WAVE FLOW FIELD TO AGREE WITH EXPERIMENTAL DATA BY USING NUMERICAL METHOD WITH HIGH IDENTIFICATION

In this paper, on the basis of experimental data of two kinds of chemical explosions, the piston-pushing model of spherical blast-waves and the second-order Godunov-type scheme of finite difference methods with high identification to discontinuity are used to the numerical reconstruction of part of an actual hemispherical blast-wave flow field by properly adjusting the moving bounary conditions of a piston. This method is simple and reliable. It is suitable to the evaluation of effects of the blast-wave flow field away from the explosion center.

Remaining useful life prediction based on the Wiener process for an aviation axial piston pump

An aviation hydraulic axial piston pump＇s degradation fiom comprehensive wear is a typical gradual failure model. Accurate wear prediction is difficult as random and uncertain char- acteristics must be factored into the estimation. The internal wear status of the axial piston pump is characterized by the return oil flow based on fault mechanism analysis of the main frictional pairs in the pump. The performance degradation model is described by the Wiener process to predict the remaining useful life （RUL） of the pump. Maximum likelihood estimation （MLE） is performed by utilizing the expectation maximization （EM） algorithm to estimate the initial parameters of the Wiener process while recursive estimation is conducted utilizing the Kalman filter method to estimate the drift coefficient of the Wiener process. The RUL of the pump is then calculated accord- ing to the performance degradation model based on the Wiener process. Experimental results indi- cate that the return oil flow is a suitable characteristic for reflecting the internal wear status of the axial piston pump, and thus the Wiener process-based method may effectively predicate the RUL of the pump.

Simultaneous blood flow and oxygenation measurements using an off-the-shelf spectrometer

Blood oxygenation and flow are both important parameters in a living body. In this Letter, we introduce a simple configuration to simultaneously measure blood flow and oxygenation using an off-the-shelf spectrometer. With the integration time of 10 ms, flow phantom measurements, a liquid blood phantom test, and an arm cuff occlusion paradigm were performed to validate the feasibility of the system. We expect this proof-of-concept study would be widely adopted by other researchers for acquiring both blood flow and oxygenation changes due to its straightforward configuration and the possibility of multimodal measurement.

Suppression effect of jet flow on pulsating pressure of cavity using scale-adaptive simulation model

The suppression of the aerodynamic noise in the cavity has a great significance to solve relevant puzzles of weapon bays. Acoustic field of the standard cavity model is simulated by using the computational fluid dynamics technology based on scale-adaptive simulation （SAS） model. The results obtained by the proposed method in this paper show reasonable agreement with experiments. On the basis of this, effect of different jet flow rates on the time-averaged variables, turbulent kinetic energy, root mean square （RMS） of sound pressure, sound sources distribution and the pulsating pressure distribution in the cavity is studied. The analysis shows that the jet flow has great influence on the cavity flow field and the distribution of pulsating pressure RMS by changing the morphology of the shear layer. The most obvious of these measures is spout4 configuration, the influence mainly in the form of reducing the pulsating pressure of the whole cavity and changing the sound pressure level in the far field. The results show that different jet flow rates have different control effects on pulsating pressure in the cavity and sound pressure level in the far field. Furthermore, the jet flow rates and the suppression effect on the pulsating pressure have no linear relation.