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Porous materials have excellent functions in filtration and purification, and gradient composite porous materials enrich the product types of porous materials in the same field. In the preparation of metal-ceramic gradient composite porous materials, the matching relationship between the pore morphology and pore size of the metal porous matrix and the coated powder particles will seriously affect the structure and performance of the ceramic membrane. This work mentions the different size range (60, 100, 200 and 400 mesh) of 316 L stainless steel powder particles as the raw materials which are at different sintering temperatures of 1170, 1200 and 1230 °C, the fabrication of porous 316 L stainless steel substrate which was made by hanging slurry preparation of precursor, at the same time using Ar protection at different sintering temperatures (650, 700, 750 and 800 °C) to the preparation of metal-ceramic composite gradient according to different matrix apertures of porous materials. The pore structure, microstructure and morphology characteristics of different samples both of matrix and functionally gradient composite were analyzed and characterized. On the basis of test of permeability of functionally gradient composite porous materials, this kind of composite gradient porous material can be excellent at part of permeability which matrix was made by 400 mesh 316 L stainless steel powder particles at sintering temperature of 1230 °C and then dealed with the process of hanging slurry to became the precursor which ceramic membrane was prepared at sintering temperature of 650 °C. Maximum aperture of the porous substrate filtration precision under the combination of ceramic membrane layer can be increased by 96.3%. By observing the change of pore morphology of porous matrix, this paper aims to make a research of influence of sintering temperature and powder particles size on permeability of the functionally gradient composite porous materials, and also provide a reference for improving the filtration accuracy of existing porous materials.

Digital sub-array synchronization is a key problem in phased array radar design. The sampling rate of ADC and DAC is a decisive index to determine the difficulty of synchronization. This paper discusses the synchronization between multi-chip ADC with 1Ghz sampling rate and DAC converter with 2.5ghz sampling rate. The key to synchronization is how to meet the timing deviation requirements of jesd204b-1 protocol for the SYSREF signal arriving at each converter. In this paper, an innovative feedback mode is adopted to adjust the signal timing sequence actively to achieve the effect of accurate synchronization, and then the design and implementation of phase array radar digital sub-array stage synchronization under high sampling rate is realized.

Feedrate scheduling is one of the most important factors of computer numerical control (CNC) machining and has become a crucial research problem. In order to improve the machining accuracy and motion smoothness, an optimized feedrate scheduling method considering round-off error compensation based on S-shaped acceleration/deceleration (ACC/DEC) algorithm is proposed in this paper. There are two main stages, namely initial feedrate scheduling and parameters calculation of round-off error compensation. In the stage of initial feedrate scheduling, a novel time rounding principle is introduced to reduce the round-off error. Meanwhile, the motion parameters of each section can be calculated based on the proposed feedrate scheduling method. The constant feedrate section used for round-off error compensation is always guaranteed to exist although the actual maximum feedrate might be smaller than the command feedrate. Then, in the stage of compensation parameters calculation, the round-off error can be obtained based on the proposed time rounding principle and the scheduled parameters should be updated. In order to maintain the continuity of the acceleration profile, the improved trapezoidal ACC/DEC algorithm is introduced to conduct the error compensation and the crucial parameters can be calculated based on its special properties. In addition, the feedrate look-ahead strategy is also tweaked to enhance the reliability of feedrate scheduling. Finally, a series of simulations and practical experiments with two non-uniform rational B-spline (NURBS) curves are conducted to verify the good performance and applicability of the proposed method.

Objective:Antrodia camphorata (AC), a precious medicinal mushroom in Taiwan, is popularly used for adjuvant cancer therapy. This paper aims to clarify the metabolites which are present in tumor tissues after oral administration of AC in Sarcoma-180 tumor-bearing mice, as well as their contents in tumors. Methods:Tumors of Sarcoma-180 tumor-bearing mice were obtained at 1 h and 4 h after oral administration of AC extract, and the metabolites in the tumor homogenate samples were characterized using UHPLC-orbitrap/MS analysis. Then, a fully validated LC-MS/MS method was developed for quantitative analysis of the most abundant compounds in tumor tissues, namely (25R/S)-antcin H. Results:A total of 33 compounds were characterized in tumor homogenate samples including 28 prototypes of triterpenoids and 5 metabolites. Among them, (25R)-antcin H and (25S)-antcin H had the highest contents of 2.03 and 0.66 μg/g tumor tissues for the 1 h group, and 2.04 and 0.59 μg/g tumor tissues for the 4 h group, respectively. It was obvious that (25R)-antcin H had higher tumor affinity than (25S)-antcin H, since the content of (25R)-antcin H was lower than that of (25S)-antcin H in AC extract (P < 0.01). Conclusion:Triterpenoids can enter tumor tissues after oral administration of AC. Particularly, (25R)-antcin H showed higher exposure to tumor than (25S)-antcin H. These compounds could contribute to the anticancer activities of AC.

In order to improve the motion smoothness while maintaining the machining efficiency of the non-uniform rational B-spline (NURBS) interpolation, a novel jerk-continuous acceleration/deceleration (ACC/DEC) algorithm and the corresponding feedrate scheduling method are proposed in this paper. The polynomial and trigonometric functions are combined to construct the jerk-continuous ACC/DEC profile. Meanwhile, to reduce the computational load of feedrate scheduling, a proportional control method is proposed to determine the form of the jerk profile, which also improves the flexibility of feedrate control. Therefore, the maximum jerk and acceleration can be maintained to achieve higher machining efficiency compared with the conventional trigonometric methods, while the feedrate scheduling process is far simpler than the polynomial methods with continuous jerk. In addition, to improve the machining accuracy and motion smoothness, the round-off error caused by cycle sampling is also considered in feedrate scheduling and real-time interpolation. The proposed ACC/DEC algorithm is simplified to achieve the round-off error compensation, which can guarantee the continuity of jerk profile. A series of simulations and experiments for two NURBS curves is conducted to verify the good performance and applicability of the proposed method.

To improve the interpolation accuracy for the non-uniform rational B-spline (NURBS) curves, this paper proposes a novel bidirectional adaptive feedrate scheduling (BAFS) method based on S-shaped acceleration/deceleration (ACC/DEC) algorithm. The NURBS interpolator with the proposed BAFS method is also presented. The BAFS method has two meanings. First, to consider the continuous constraints of feedrate especially in the areas near the endpoints of each NURBS curve segment, an adaptive feedrate scheduling method is designed, which can improve the interpolation accuracy compared with the conventional method only considering the constraints of endpoints. Second, a bidirectional adaptive interpolation strategy including an adaptive task scheduling method and a meeting processing method is proposed to conduct the acceleration and deceleration interpolation stages of each NURBS segment separately in two directions. The two directions interpolation can be realized orderly by the adaptive task scheduling and the smoothness of feedrate profile can be guaranteed by the meeting processing method whose solvability is also proved. Therefore, the feedrate constraints at both the start and end points areas can be considered, which can improve the interpolation accuracy. Meanwhile, the round-off errors caused by cycle sampling are also considered and compensated in the bidirectional feedrate scheduling process to maintain the motion smoothness. In addition, an optimized look-ahead strategy is designed to ensure the correctness of the endpoints feedrate. Finally, a series of simulations and experiments are conducted to validate the good performance and applicability of the proposed method.

This paper aims at the power supply problem of different types of rural users in rural power supply system. It comprehensively considers factors such as rural load density, power supply radius, load characteristics, distributed energy distribution and other factors, combined with the development of different rural areas. The principles of local consumption, practical networking, and other proposals put forward a power supply model for remote areas in eastern Inner Mongolia. By discussing the two methods of decentralized microgrid power supply and centralized power supply, a specific power supply scheme was derived to enable it to solve the local power supply problem.