Microstructural Evolution and Mechanical Properties of a Continuously Cast Al–Mg–Si–Cu Alloy Processed by Repetitive Continuous Extrusion Forming

Long Zhang,Ruiqing Lu,Jie Tang,Fulin Jiang,Dingfa Fu,Hui Zhang,Jie Teng 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.7

A continuously cast Al–Mg–Si–Cu alloy was processed by repetitive continuous extrusion forming (R-Conform) and thecorresponding deformation behaviors, microstructural evolution and mechanical properties were investigated systematicallyby combining uniaxial compression deformation, finite element simulation, microstructural observation and mechanicaltest. The results showed that the grain size of Al–Mg–Si–Cu alloy bar was gradually refined and became more uniformafter R-Conform processing with the increase of pass as a result of continuous dynamic recrystallization. The evolution ofmicrostructure was related to the complex thermomechanical conditions of temperature, shear rate and the distribution ofaccumulated strain during R-Conform process. Then the improvement of properties was obtained by the refined grains afterR-Conform processing. Further, the dense and fine precipitates formed after solution treatment and aging led to optimizedmechanical properties with tensile strength approximate 400 MPa and elongation about 17.8%.

The Production and Cytological Analysis of Brassica napus-B Genome Chromosome Monosomic Addition Lines and Their Hybrids

Mao Teng Li,Jun Xiang,Jian Min Liu,Long Jiang Yu,Dian Rong Li 한국유전학회 2008 Genes & Genomics Vol.30 No.2

The Brassica napus-B genome monosomic addition lines (MALs) (AACC + B`, 2n = 39) were developed from self-pollination of pentaploid hybrids (AABCC) that were derived from hybridization between hexaploid hybrids (AABBCC) and B. napus (AACC). The alien chromosomes of the B genome in MALs were identified by the GISH technique, by observation of the meiotic behavior of pollen mother cells (PMCs), and by B-genome-specific molecular marker analysis. Studies of the meiotic behavior of B. napus-B genome chromosome MALs at diakinesis revealed that the majority of the chromosome configuration was 19II+1I, which indicated that the alien B genome chromosome remained univalent in most cases. The laggard-free PMCs also appeared at a lower ratio, which indicated that the B genome chromosome could be transmitted into gametes. The chromosome configurations of 20II and 19II+2I that appeared in double MALs (AACC+ 2 chromosomes of the B genome) indicated different homoeology between different B genome chromosomes. The paired B genome bivalent in double MALs can be normally segregated at anaphase in most cases. PMCs with multivalents were observed in all the double MAL combinations, which indicated homology of the B genome chromosomes with the A or C genome chromosomes.

Heavy concrete shielding properties for carbon therapy

Jin-Long Wang,Jiade J Lu,Da-Jun Ding,Wen-Hua Jiang,Ya-Dong Li,Rui Qiu,Hui Zhang,Xiao-Zhong Wang,Huo-Sheng Ruan,Yan-Bing Teng,Xiao-Guang Wu,Yun Zheng,Zi-Hao Zhao,Kai-Zhong Liao,Huan-Cheng Mai,Xiao-Dong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

論宋代法律文明對社會歷史發展的積極作用

Wang, Xiao-long(王曉龍),Teng, Zi-he(滕,子赫) 한국외국어대학교 역사문화연구소 2014 역사문화연구 Vol.51 No.-

宋朝는 中國法制史에서 唐朝 이후에 가장 빛난 업적을 이루었던 시기이고, 元ㆍ明ㆍ淸과 동시대의 서방과 비교해보아도 法律制度의 設計와 執行에 있어서 이들과 비교하여 文明化 되어가는 특징을 보여주는 시기이다. 송대 법률이 문명화는 국가정권의 안정과 吏治의 淸明함을 촉진시켰고, 司法의 公正과 사회모순의 불균형을 감소시켰다. 經濟法과 財政稅收法 등은 農業ㆍ手工業ㆍ商業과 같은 분야의 발전을 촉진시켰고, 국가 재정 수입을 확보하였으며 송조가 중국 경제사에서 전성기를 맞이할 수 있는 역할을 하였다. 民事法律의 제정과 개선은 중국사에서 법률의 기초가 되는 "重刑輕民"의 전통을 보완하는 역할을 하여 부녀자ㆍ노약자ㆍ장애인과 같은 사회 약자층의 權益을 보호하였다. 그리고 文化敎育ㆍ書籍出版ㆍ輿情收集 등의 방면에 法을 확립하였으며, 이와 관련된 분야의 발전과 여론의 개방을 촉진하였다. 송대 법률 문명화로의 발전은 송대 이후의 왕조들이 法制를 완성하는데 큰 영향을 끼쳤다. Compared with the Yuan Ming and Qing Dynasties and even the same period of the western countries, the Song Dynasty is the most glorious era after the Tang Dynasty in Chinese legal history.Its legal system shows more prominent civilization trend in the design and execution. The legal civilization of Song Dynasty promoted the stability of the state power and the integrity of the officials, maintained the judicial justice and reduced the social conflicts. The Economic Law and the Fiscal and Tax Law promoted agriculture, handicraft industry and business fields, guaranteed the national fiscal revenues and made the Song Dynasty to be another peak of the economic history in ancient China. Its adjustment and improvement to the Civil Law, in part make up for the tradition of "value the panalty and despise the people"in Chinese ancient law, and preferably maintained the rights of the social vulnerable groups such as women, young and old, orphans and the disabled. And the legislation on cultural education, book publishing and public opinion collection also promoted the development of the related fields and the freedom of public opinion.

Experimental study and analysis of design parameters for analysis of fluidelastic instability for steam generator tubing

Guangming Xiong,Yong Zhu,Teng Long,Wei Tan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1

In this paper, the evaluation method of fluidelastic instability (FEI) of newly designed steam generator tubing in pressurized water reactor (PWR) nuclear power plants is discussed. To obtain the parameters for prediction of the critical velocity of FEI for steam generator tubes, experimental research is carried out, and the design parameters are determined. Using CFD numerical simulation, the tube array scale of the model experiment is determined, and the experimental device is designed. In this paper, 7 groups of experiments with void fractions of 0% (water), 10%, 20%, 50%, 75%, 85% and 95% were carried out. The critical damping ration, fundamental frequency and critical velocity of FEI of tubes in flowing water were measured. Through calculation, the total mass and instability constant of the immersed tube are obtained. The critical damping ration measured in the experiment mainly included two-phase damping and viscous damping, which changed with the change in void fraction from 1.56% to 4.34%. This value can be used in the steam generator design described in this paper and is conservative. By introducing the multiplier of frequency and square root of total mass per unit length, it is found that the difference between the experimental results and the calculated results is less than 1%, which proves the rationality and feasibility of the calculation method of frequency and total mass per unit length in engineering design. Through calculation, the instability constant is greater than 4 when the void fraction is less than 75%, less than 4 when the void fraction exceeds 75% and only 3.04 when the void fraction is 95%.

Research on the Security Threats and Strategy in Smart Grid Application

Ding, Guanjun,Fan, Bangkui,Long, Teng,Lan, Haibin,Wang, Jing,Chen, Zhiyong The Korean Institute of Electrical Engineers 2014 The Journal of International Council on Electrical Vol.4 No.3

The smart grid is evolving rapidly from a relatively isolated environment to an opened one. The adoption of information and communication technologies can make greater connectivity and interoperability between components. However, the increased connectivity also brings the challenge to security. First of all, in allusion to the current study on security threats to smart grid simple and deficient, the paper induces and analyzes it thoroughly, which can also correct some misunderstanding in a certain degree, from the view of system level, services, confidentiality and so on. Secondly, based on the analysis of security threats, the paper constructs the security strategy for smart grid. It consists of four steps, which are discussed detailedly one by one. It can provide the protection effectively. Finally, relevant conclusions are made.

Cyclophosphamide-induced HCN1 channel upregulation in interstitial Cajal-like cells leads to bladder hyperactivity in mice

Qian Liu,Zhou Long,Xingyou Dong,Teng Zhang,Jiang Zhao,Bishao Sun,Jingzhen Zhu,Jia Li,Qingqing Wang,Zhenxing Yang,Xiaoyan Hu,Longkun Li 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively. Cyclophosphamide (CYP)-induced cystitis models were successfully established in these mice. CYP treatment significantly enhanced HCN channel protein expression and Ih density and significantly altered bladder HCN1 channel regulatory proteins. Carbachol (CCH) and forskolin (FSK) exerted significant effects on bladder ICC-LC [Ca2+]i in CYP-treated wild-type (WT) mice, and HCN1 channel ablation significantly decreased the effects of CCH and FSK on bladder ICC-LC [Ca2+]i in both naive and CYP-treated mice. CYP treatment significantly potentiated the spontaneous contractions and CCH (0.001–10 μM)-induced phasic contractions of detrusor strips, and HCN1 channel deletion significantly abated such effects. Finally, we demonstrated that the development of CYP-induced bladder overactivity was reversed in HCN1 / mice. Taken together, our results suggest that CYP-induced enhancements of HCN1 channel expression and function in bladder ICC-LCs are essential for cystitis-associated bladder hyperactivity development, indicating that the HCN1 channel may be a novel therapeutic target for managing bladder hyperactivity.

Generalized Vector Control with Reactive Power Control for Brushless Doubly-Fed Induction Machines

Qiwei Duan,Shi Liu,H. Inaki Schlaberg,Teng Long 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

In this paper, a current hysteresis control with good decoupling properties for doubly-fed brushless induction machines (BDFIMs) has been proposed based on a generalized vector model. The independent control of the reactive power and speed for BDFIMs has been achieved by controlling the d-axis and the q-axis current of the control windings (CW). The proposed vector control method has been developed for the power winding (PW) flux frame. Experimental verification of a type Y180M-4 BDFIM prototype with 1/4 pole-pairs has been presented. Evidence of its good performance has been shown through experimental results.

Generalized Vector Control with Reactive Power Control for Brushless Doubly-Fed Induction Machines

Duan, Qiwei,Liu, Shi,Schlaberg, H. Inaki,Long, Teng The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

In this paper, a current hysteresis control with good decoupling properties for doubly-fed brushless induction machines (BDFIMs) has been proposed based on a generalized vector model. The independent control of the reactive power and speed for BDFIMs has been achieved by controlling the d-axis and the q-axis current of the control windings (CW). The proposed vector control method has been developed for the power winding (PW) flux frame. Experimental verification of a type Y180M-4 BDFIM prototype with 1/4 pole-pairs has been presented. Evidence of its good performance has been shown through experimental results.

Low Chattering Trajectory Tracking Control of Non-singular Fast Terminal Sliding Mode Based on Disturbance Observer

Jiqing Chen,Chaoyang Zhao,Qingsong Tang,Xu Liu,Zhikui Wang,Chengzhi Tan,Jiahua Wu,Teng Long 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.2

The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified. The improvement of the performance of the multi-joint manipulator control system is of great significance to improve the level of industrial automation. The existing sliding mode control methods are difficult to ensure the high-precision and fast-tracking of joints of a manipulator to the desired trajectory under low chattering control input. Therefore, a non-singular fast terminal sliding mode control method based on a nonlinear disturbance observer is proposed. In addition, a new non-singular fast terminal sliding mode surface is designed. The performance comparison method of the sliding mode surface proves its better control quality. Aiming at the problem of serious chattering, the nonlinear disturbance observer technology, and saturation function method are introduced to effectively weaken the chattering. Finally, taking the 3-DOF manipulator as the research object, a comparative simulation experiment is carried out in the MATLAB / Simulink environment. The results show that under the uncertainty of modeling error, external disturbance, and joint friction, the designed control method not only solves the problems of singular control input and serious chattering but also realizes the high-precision and fast-tracking of each joint to the desired trajectory. Thus, the effectiveness and feasibility of the design method are verified.