An Observing Method for Flux and Speed with Direct Torque Control

An observing method for stator flux and rotor flux is presented. Based on the proposed flux observing method, a novel speed estimator has been designed. At last, the speed estimator combined with the flux observing is applied in the direct torque control system without speed sensor. The simulation results show that these methods can improve the accuracy of speed observing and the low speed performance of direct torque control system, and strengthen the robustness of system.     

蒸发时间对两级凝胶法制备的聚醚砜膜结构和性能的影响

主要探讨了蒸发时间对用两级凝胶法(dual—bath coagulation method)所制得的聚醚砜(PES)超滤膜的性能和结构的影响．结果表明，随着蒸发时间的延长，水通量先减小后增大；肌肝和尿素去除率均是先升高而后降低，然后再升高的趋势；膜的孔隙率上升，平均孔径下降．在蒸发时间为10s时，肌肝和尿素去除率最高，且水通量适中，是血液净化用聚醚砜膜的最佳成形条件．     

预处理剂对陶瓷膜表面性质及渗透通量的影响

考察了不同预处理剂对陶瓷膜表面性质及渗透通量的影响,结果表明:表面活性剂的加入,使陶瓷膜表面的负电性以及亲水性得到提高,膜渗透通量从100L/(m2·h)提高到200L/(m2·h);碱式氯化铝中Al3+在膜表面的吸附,导致膜表面呈现正电位,相应的膜渗透通量只有50L/(m2·h);吸附剂对渗透通量的影响主要体现其在乳化废水中表面电位的不同,呈负电性的二氧化硅有利于渗透通量的提高,而呈正电性的氧化铝会导致膜通量的下降.     

Design and performance of compensator for decremental persistent current in HTS magnets using linear type magnetic flux pump

This paper has described the characteristics of a stationary linear type magnetic flux pump newly developed this time. The linear type flux pump aims to compensate a little decremental persistent current of the HTS magnet in NMR and MRI systems. The flux pump mainly consists of DC bias coil, 3-phase AC coil and Nb foil. Analytical results by the FEM are proved to nearly agree with experimental ones. In the experiment, it has been investigated that the flux pump can effectively charge the current in the load coil of 1.3 mH for various frequencies in 150 s under two following conditions: (1) DC bias of 10 A and AC of 4 A_rms, (2) DC bias of 10 A and AC of 5 A_rms. The maximum magnitudes of initial increasing rate of pumping current and load magnet voltage are: (1) 0.2 A/s and 25 mV and (2) 0.22 A/s and 34 mV, respectively.     

Non-Newtonian Fluids in Spout-Fluid Beds: Mass Transfer Coefficient at Low Reynolds Numbers

Following on from the work of Anabtawi et al. (2003), this study examined how the volumetric liquid-phase mass transfer coefficient, k_La, of oxygen in air in three-phase spout-fluid beds was affected by varying the system parameters of bed height, bed diameter, gas velocity, and liquid velocity. The liquid used was 0.1% CMC solution, displaying a pseudo-plastic rheology, with 1.75 mm glass spheres as packing. The values of the Sherwood number were lower than in previous studies (Anabtawi et al., 2003), in the range 9,000-186,000. Gas velocity had a similar effect on k_La as in a bubble column, with results also giving good agreement with previous work on two-phase and three-phase spouted bed systems. The correlation obtained for the effect of liquid velocity on k_La compared well with that of Schumpe et al. (1989). An increase in the height of packing increased k_La to the power of 0.319, with an increase in column diameter also causing an increase in k_La, which is in agreement with the results of Akita and Yoshida (1973).     

Flux, Pulse, and Spin: Dynamic Additions to the Personality Lexicon.

Personality constructs were proposed to describe intraindividual variability in interpersonal behavior. Flux refers to variability about an individual's mean score on an interpersonal dimension and was examined for the 4 poles of the interpersonal circumplex. Pulse and spin refer to variability about an individual's mean extremity and mean angular coordinate on the interpersonal circumplex. These constructs were measured using event-contingent recording. Latent state-trait analyses indicated high stability of flux in submissive, agreeable, and quarrelsome behaviors and some stability in the flux of dominance. Further analyses indicated moderate to high stability in pulse and spin. Neuroticism predicted greater pulse, spin, and submissive behavior flux. Extraversion predicted greater flux in agreeable behavior. In contrast, Agreeableness predicted reduced spin and quarrelsome behavior flux. Social environmental variables predicted greater flux in dominant behavior. Flux, pulse, and spin provide reliable and distinctive additions to the vocabulary for describing individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new instrument for passive remote sensing: 2. Measurement of leaf and canopy reflectance changes at 531 nm and their relationship with photosynthesis and chlorophyll fluorescence

A previously described passive remote sensing fluorimeter (see companion paper) was modified to detect changes in the reflectance of vegetation. The utility of this remote sensing technique to measure the Physiological Reflectance Index (PRI) is shown at both leaf level under laboratory conditions and at the canopy level in the field. PRI, defined as the relative changes in reflectance at 531 nm with respect to those at 570 nm (PRI=R531−R570/R531+R570), is related to xanthophyll-related, dynamic changes of non-photochemical quenching of chlorophyll fluorescence. The robustness of this relationship by simultaneous remote sensing of PRI and chlorophyll fluorescence is strengthened. At the leaf level, the existence of two kinetically distinct components of PRI is shown. A fast (within seconds) component that is partly attributed to ΔpH induced chloroplast shrinkage, and a slow (within minutes), main component that is related to xanthophyll de-epoxidation, as demonstrated by its disappearance in the presence of DTT. Overall, PRI correlated better with non-photochemical quenching of chlorophyll fluorescence (NPQ) than with any other measured parameter, including the photochemical efficiency of PSII. Finally, at the canopy level and under field conditions, it is shown that PRI can be a useful tool for remote sensing of water stress in grapevines.     

液钠沸腾两相流流型与临界热流密度(CHF)机理实验研究

通过大量的液态金属钠临界热流密度 (CHF)的实验研究 ,结合液钠两相传热流动特性及液钠的物性特点 ,分析了起始沸腾流型 ,泡状流 ,块状流 ,环状流和双向环状流的热工水力特性 ;并从实验结果出发 ,深入分析了液钠发生临界热流密度时的气泡爆炸和液膜撕裂或局部蒸干的两种传热恶化机理     

三氯化钛还原-重铬酸钾滴定法测定球团矿中TFe

采用碱混合熔剂熔融试样,熔融物以热水浸取盐酸酸化后,用SnCl2-TiCl3将Fe3+还原为Fe2+,以钨酸钠为指示剂指示还原终点;在硫磷混酸介质中,以二苯胺磺酸钠为指示剂,用重铬酸钾标准溶液滴定球团矿中TFe含量。该法测定TFe的绝对误差<0.15%,避免了用重铬酸钾氧化褪去钨蓝色泽时易引入的误差。     

用灰色系统理论预测环形通道内液钠的临界热流密度

用灰色系统理论对在两台液钠沸腾实验回路上测得的实验数据进行了钠沸腾临界热流密度（CHF）值影响因素的灰色相关分析,并用GM（1,1）模型对CHF进行预测,选用GM（1,h)模型对CHF进行了建模,计算及预测结果与实验值符合较好。