Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

Object Web 基盤의 OSI 망 管理

김강석,송왕철 濟州大學校工科大學産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.2

The Object web translates the existing CORBA IDL into the Java language and uses IIOP for interaction between a client and a server under the exiting Web environment. The client and the server through the Object Web. do not use HTTP, a web protocol, but IIOP that is an inter-object communication protocol provided by the CORBA. This paper proposes an architecture which consists of a gateway, a CORBA manager and an OSI agent. The CORBA manager is based on Object Web and can manage MOs in the OSI domain. The gateway has a role to translate CORBA IDLS into CMIS service and vice versa. Hence, an OSI agent can be abstracted into a CORBA agent. In this architecture, any client with the Web browser can manage OSI MOs in distributed environment. The client can invoke the management operations through CORBA server after it download the Java applet from HTTP server.

JNDI를 이용한 Mobile Agent 기반 망관리시스템

김정철,김강석,송왕철 濟州大學校 産業技術硏究所 1999 산업기술연구소논문집 Vol.10 No.2

Recently, network management technology by delegation has been studied as a kind of network management technology to satisfy the user's requirements. Mobile Agent in the technology issues in the distributed network system. Mobile Agent is a software program which is able to move on network with mission for managing a NE(Network Element). Therefore. We have studied the efficient network management technology which is the network management system based upon Mobile Agent Using JNDI(Java Naming Directory Interface). JNDI is API(App1ication Program Interface) to support interface which make user's application program to be used the naming & directory service. We have designed and implemented the mobile agent network management system using JNDI. This Mobile Agent system is expected to provide a solution for the conventional centralized network system.

JNDI를 이용한 Mobile Agent 기반 망관리시스템

김정철,김강석,송왕철 제주대학교 산업기술연구소 1999 尖端技術硏究所論文集 Vol.10 No.2

Recently, network management technology by delegation has been studied as a kind of network management technology to satisfy the user's requirements. Mobile Agent in the technology issues in the distributed network system. Mobile Agent is a software program which is able to move on network with mission for managing a NE(Network Element). Therefore, We have studied the efficient network management technology which is the network management system based upon Mobile Agent Using JNDI(Java Naming Directory Interface). JNDI is API(Application Program Interface) to support interface which make user's application program to be used the naming & directory service. We have designed and implemented the mobile agent network management system using JNDI. This Mobile Agent system is expected to provide a solution for the conventional centralized network system.

Grouting to Prevent Sulfate Corrosion on Coal Mine Shaft

Gang-Gang Xu,Shuan-Cheng Gu,Xiao-Dong Wang,Hai Wang,Shi-Bin Zhu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.11

In the area of high sulfate concentration in China, the problem of sulfate corrosion in coal mine shaft is increasingly prominent. Currently, shaft repair methods are limited to diversion, interception, and backwall grouting. However, after conventional cement stabilization, shafts still must contend with poor durability and weak resistance to sulfate corrosion. To solve these problems, this study combined theoretical research, laboratory tests, and field tests to reveal the corrosion mechanism of shafts, explored novel anti-sulfate corrosion grout, and built a model for the migration of sulfate ions (SO42−) in strata and shafts. According to the results of this study, shaft corrosion was a process of continuous penetration towards the concrete interior following a cycle of concrete compaction, expansion, and cracking. Laboratory tests show that the specimens of ordinary Portland cement mortar with 20 – 30% fly ash not only have good long-term strength, but also have a significantly improved resistance capacity to sulfate solution. Based on the laboratory test results, the HSR42.5 mixed with 20% fly ash was used for wall grouting, and the water-cement ratio of the slurry was 1:1. After wall grouting, the water inflow was effectively controlled in the grouting area in the main shaft, auxiliary shaft, and air shaft, reducing from 18.5 m3/h, 20.9 m3/h, and 10.0 m3/h to 3.5 m3/h, 4.6 m3/h, and 3.2 m3/h, respectively. Moreover, after nearly three years of continuous monitoring, the water inflow did not show any significant increase in the shafts. Based on the migration law of SO42− in concrete, a shaft geological model and a salt solution migration model after grouting reinforcement under sulfate corrosion conditions were constructed. In addition, the analysis of the migration law of sulfate ion in the shaft and grouting reinforcement formation revealed that the service period of the grouting shaft can be extended for approximately 6 – 8 years.

Mineralogy and isotope geochemical characteristics for Xiaozhen copper deposit, Langao County, Shaanxi Province and their constraint on genesis of the deposit

Gang Wang,Zong-qi Wang,Rui Shi,Ying-li Zhang,Kun-ming Wang 한국지질과학협의회 2015 Geosciences Journal Vol.19 No.2

The Xiaozhen copper deposit is a typical deposit in the North Daba Mountain area polymetallic metallogenic belt. With the exception of geological prospecting research, however, few studies have been reported on the genesis of the deposit. This paper focuses on the mineralogical and isotope geochemical characteristics for the Xiaozhen copper deposit. Detailed field-work and microscope observations suggest that the ore’s structural fabric and mineral assemblages feature a medium–low-temperature hydrothermal pattern of metallogeny. The results of electron microprobe analysis indicate that chalcopyrite atomic ratio ΣMe/S = ~0.95–1.03, which suggests that they may not be of sedimentary origin. In addition, the S content of the pyrite is from 50.57 wt% to 53.16 wt% that is less than standard the value of 53.45 wt%, the Fe/S value is from 0.878 to 0.955, and the Ni content in pyrite is high even up to 0.38 wt%. These results, combined with Ni-Co graphic projection, indicate that the pyrite is of magmatic hydrothermal origin. Moreover, most of the sphalerites contain Se, and their calculated w(FeS) content ranging from 4.60 wt% to 10.37 wt% suggest magmatic origin and a formation temperature of approximately 300 °C. Further, the content of χ(Fe) is from 46.55 wt% to 46.97 wt% for pyrrhotites, suggesting they are clino-pyrrhotites. This result, combined with mineral assemblages and the Fe-S system diagram, indicates a mineralization temperature of approximately 310 °C. The δ34S values of the sulfide range from 2.6‰ to 11.5‰, indicating multisource properties. The 208Pb/204Pb has wider ratios (~38.897–39.918), reflecting that they contain abundant radiogenic lead. The Pb isotope tectonic setting and genetic classification plot show that the ore lead was provided mainly by the upper crust in addition to a few magma materials. The analytical results of fluid inclusions in the chalcopyrite show that the 3He/4He ratios are ~0.268–0.326 R/Ra, which is higher than the crustal ratios but grossly lower than that of the mantle fluid and that the 40Ar/36Ar ratios are higher than the argon isotopic composition of the atmosphere. Moreover, the He-Ar isotope system suggests that the source of the ore-forming fluids is predominantly meteoric low-temperature underground water, with a small amount of mantle fluid. In summary, this study has determined that the Xiaozhen copper deposit is a medium-temperature magmatic hydrothermal deposit. This finding is combined with metallogenic age to briefly describe the mineralization process.

Exploring the role and mechanisms of diallyl trisulfide and diallyl disulfide in chronic constriction-induced neuropathic pain in rats

( Gang Wang ),( Yan Yang ),( Chunfeng Wang ),( Jianzhong Huang ),( Xiao Wang ),( Ying Liu ),( Hao Wang ) 대한통증학회 2020 The Korean Journal of Pain Vol.33 No.3

Background: Garlic oil is a rich source of organosulfur compounds including diallyl disulfide and diallyl trisulfide. There have been studies showing the neuroprotective actions of these organosulfur compounds. However, the potential of these organosulfur compounds in neuropathic pain has not been explored. The present study was aimed at investigating the pain attenuating potential of diallyl disulfide and diallyl trisulfide in chronic constriction injury (CCI)-induced neuropathic pain in rats. The study also explored their pain-attenuating mechanisms through modulation of H₂S, brain-derived neurotrophin factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf2). Methods: The rats were subjected to CCI injury by ligating the sciatic nerve in four places. The development of neuropathic pain was measured by assessing mechanical hyperalgesia (Randall-Selittotest), mechanical allodynia (Von Frey test), and cold allodynia (acetone drop test) on 14th day after surgery. Results: Administration of diallyl disulfide (25 and 50 mg/kg) and diallyl trisulfide (20 and 40 mg/kg) for 14 days led to a significant reduction in pain in CCI-subjected rats. Moreover, treatment with these organosulfur compounds led to the restoration of H₂S, BDNF and Nrf2 levels in the sciatic nerve and dorsal root ganglia. Coadministration of ANA-12 (BDNF blocker) abolished pain attenuating actions as well as BDNF and the Nrf2 restorative actions of diallyl disulfide and diallyl trisulfide, without modulating H₂S levels. Conclusions: Diallyl disulfide and diallyl trisulfide have the potential to attenuate neuropathic pain in CCI-subjected rats possibly through activation of H₂S-BDNF-Nrf2 signaling pathway.

ATM Signaling Pathway Is Implicated in the SMYD3-mediated Proliferation and Migration of Gastric Cancer Cells

Wang, Lei,Wang, Qiu-Tong,Liu, Yu-Peng,Dong, Qing-Qing,Hu, Hai-Jie,Miao, Zhi,Li, Shuang,Liu, Yong,Zhou, Hao,Zhang, Tong-Cun,Ma, Wen-Jian,Luo, Xue-Gang The Korean Gastric Cancer Association 2017 Journal of gastric cancer Vol.17 No.4

Purpose: We previously found that the histone methyltransferase suppressor of variegation, enhancer of zeste, trithorax and myeloid-nervy-deformed epidermal autoregulatory factor-1 domain-containing protein 3 (SMYD3) is a potential independent predictive factor or prognostic factor for overall survival in gastric cancer patients, but its roles seem to differ from those in other cancers. Therefore, in this study, the detailed functions of SMYD3 in cell proliferation and migration in gastric cancer were examined. Materials and Methods: SMYD3 was overexpressed or suppressed by transfection with an expression plasmid or siRNA, and a wound healing migration assay and Transwell assay were performed to detect the migration and invasion ability of gastric cancer cells. Additionally, an MTT assay and clonogenic assay were performed to evaluate cell proliferation, and a cell cycle analysis was performed by propidium iodide staining. Furthermore, the expression of genes implicated in the ataxia telangiectasia mutated (ATM) pathway and proteins involved in cell cycle regulation were detected by polymerase chain reaction and western blot analyses. Results: Compared with control cells, gastric cancer cells transfected with si-SMYD3 showed lower migration and invasion abilities (P<0.05), and the absence of SMYD3 halted cells in G2/M phase and activated the ATM pathway. Furthermore, the opposite patterns were observed when SMYD3 was elevated in normal gastric cells. Conclusions: To the best of our knowledge, this study provides the first evidence that the absence of SMYD3 could inhibit the migration, invasion, and proliferation of gastric cancer cells and halt cells in G2/M phase via the ATM-CHK2/p53-Cdc25C pathway. These findings indicated that SMYD3 plays crucial roles in the proliferation, migration, and invasion of gastric cancer cells and may be a useful therapeutic target in human gastric carcinomas.

T-spline surface smoothing based on 1-ring neighborhood space angle

Wang Aizeng,Li Ling,Chang Heng,Zhao Gang,Wang Wei,Yang Jiaming 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.4

The prominent properties owned by T-spline, such as flexibility, continuity, local refinement, water tightness, make it extensively applied in Computer Aided Design (CAD)- and Computer Aided Engineering (CAE)-integrating scenarios. But the local fairness may dissatisfy in damaged areas or even on the entire surface of industry applications. Under these circumstances, local protrusion and sharp features appeared seriously affect the fairness of T-spline surfaces. Derived from the geometric properties of T-spline control points, we propose a smoothing algorithm based on the 1-ring neighborhood space angle to deal with local abruptions of T-spline surfaces. We also demonstrate the availability of the proposed algorithm through several experiments. Results show that this method is suitable for removing sharp features and smoothing unstructured T-spline surfaces.

A Multi-group Multi-agent System Based on Reinforcement Learning and Flocking

Gang Wang,Jian Xiao,Rui Xue,Yongting Yuan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.7

In this paper, we present an inter-group confrontation and intra-group cooperation method for a predator group and prey group, and construct a multi-group multi-agent system. We model the motion of the prey group using the flocking control algorithm. The prey group can cooperatively avoid predators and maintain the integrity of the group after the predators have been detected. The autonomous decision-making of the predator group is implemented based on the distributed reinforcement learning algorithm. To efficiently share the learning experience among agents in the predator group, a distributed cooperative reinforcement learning algorithm with variable weights is proposed to accelerate the convergence of the learning algorithm. Simulations show the feasibility of this proposed method.