http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Flexural Performance of Prestressed Beams with Grouting Material of Various Compactnesses
Xuansheng Cheng,Haibo Liu,Jiaxuan Su,Liang Ma,Guoliang Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.8
Presently, there is no reliable conclusion on the effect of grouting compactness on the mechanical behavior of a prestressed concrete structure. To study the influence of grouting compactness on the performance of prestressed concrete, the flexural behaviors of 8 prestressed beams fabricated by using different sheaths materials with grouting material of various compactnesses were studied experimentally, and the flexural bearing capacity and flexural stiffness of the prestressed beams were discussed. The results showed that the variation in the average strain along the beam height has a linear distribution. The load-deflection curves included two turning points, which indicate concrete cracking and steel yielding. The effect of grouting compactnesses on the early stage of beam cracking is small, but the effect becomes increasingly obvious after beam cracking. The distribution of cracks in the prestressed beams with fuller grouting is more concentrated compared to that of beams with lower grouting compactness; when the crack spacing is smaller, the beam ductility is reduced, and the bearing capacity is improved. The fracture resistance and overall bearing capacity of metal sheaths prestressed concrete beams are better than those of plastic sheaths prestressed concrete beams. However, the ductility of prestressed beams with plastic sheaths is better than that of prestressed beams with metal sheaths. A reference is provided for such prestressed concrete beams, but in practical engineering, the relevant parameters should be reevaluated because the number of studied samples is limited.
Evaluation of energy correction algorithm for signals of PET in heavy-ion cancer therapy device
Niu, Xiaoyang,Yan, Junwei,Wang, Xiaohui,Yang, Haibo,Ke, Lingyun,Chen, Jinda,Du, Chengming,Zhang, Xiuling,Zhao, Chengxin,Kong, Jie,Su, Hong Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.1
In order to solve the contradiction between requirements of high sampling rate for acquiring accurate energy information of pulses and large amount of data to be processed timely, the method with an algorithm to correct errors caused by reducing the sampling rate is normally used in front-end read-out system, which is conductive to extract accurate energy information from digitized waveform of pulse. The functions and effects of algorithms, which mainly include polynomial fitting with different fitting times, double exponential function fitting under different sampling modes, and integral area algorithm, are analyzed and evaluated, and some meaningful results is presented in this paper. The algorithm described in the paper has been used preliminarily in a prototype system of Positron Emission Tomography (PET) for heavy-ion cancer therapy facility.
A real-time sorting algorithm for in-beam PET of heavy-ion cancer therapy device
Ke, Lingyun,Yan, Junwei,Chen, Jinda,Wang, Changxin,Zhang, Xiuling,Du, Chengming,Hu, Minchi,Yang, Zuoqiao,Xu, Jiapeng,Qian, Yi,She, Qianshun,Yang, Haibo,Zhao, Hongyun,Pu, Tianlei,Pei, Changxu,Su, Hong Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.10
A real-time digital time-stamp sorting algorithm used in the In-Beam positron emission tomography (In-Beam PET) is presented. The algorithm is operated in the field programmable gate array (FPGA) and a small amount of registers, MUX and memory cells are used. It is developed for sorting the data of annihilation event from front-end circuits, so as to identify the coincidence events efficiently in a large amount of data. In the In-Beam PET, each annihilation event is detected by the detector array and digitized by the analog to digital converter (ADC) in Data Acquisition Unit (DAQU), with a resolution of 14 bits and sampling rate of 50 MS/s. Test and preliminary operation have been implemented, it can perform a sorting operation under the event count rate up to 1 MHz per channel, and support four channels in total, count rate up to 4 MHz. The performance of this algorithm has been verified by pulse generator and <sup>22</sup>Na radiation source, which can sort the events with chaotic order into chronological order completely. The application of this algorithm provides not only an efficient solution for selection of coincidence events, but also a design of electronic circuit with a small-scale structure.