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 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.

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.

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.

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.

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.

One-step and in-situ catalytic synthesis of acrylates from acetates (or propionates) and trioxane at room temperature

Gang Wang,Hui Wang,Chunshan Li,Cuncun Zuo,Zengxi Li,Suojiang Zhang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.55 No.-

One-step synthesis of acrylates from acetates and trioxane via aldol reaction at 623 K–653 K was reported. But proceeding this process at room temperature is still a challenge due to ester activation and trioxane decomposition. Herein, series of acrylates were firstly achieved, with the one-step and in-situ catalytic strategy, from acetates (or propionates) and trioxane at 293 K. Selectivity of product reaches up to 94.4% with a 80.8% yield. 1H NMR confirmed the soft enolization of ester, the decomposition of trioxane was catalyzed by TMSOTf, and the generated ionic liquid has catalytic performance on aldol condensation step.

중국의 인삼연구 ( Ginseng Research in China During The Past 20 Years )

Wang Zhen Gang 고려인삼학회 1996 Journal of Ginseng Research Vol.20 No.4

Inhibition of Proliferation and Induction of Apoptosis by the Combination of β-carotene and 1,25-dihydroxyvitamin D3 in Human Esophageal Cancer EC9706 Cells

Wang, Shao-Kang,Yang, Lei,Wang, Ting-Ting,Huang, Gui-Ling,Yang, Li-Gang,Sun, Gui-Ju Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Esophageal cancer is a common malignant tumor occurring in human esophageal epithelial tissue. The primary purpose of this paper was to define the effects of ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$, alone and in combination, on cell proliferation, cell cycle and apoptosis of human esophageal cancer EC9706 cells. Treatment with different concentrations of ${\beta}$-carotene and/or 1,25-dihydroxyvitamin $D_3$. MTT assay showed that ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$ significantly inhibited proliferation of EC9706 cells in a dose- and time-dependent manner. Further studies also demonstrated that ${\beta}$-carotene alone or 1,25-dihydroxyvitamin $D_3$ alone caused a marked increase on the induction of apoptosis in EC9706 cells. The percentage of G0/G1-phase cells significantly increased on addition of 1,25-dihydroxyvitamin $D_3$ alone, but there were no significant changes with ${\beta}$-carotene alone. These two agents in combination synergistically inhibited cell growth and induced apoptosis. Therefore, our results indicate that ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$ in combination may provide a novel strategy for preventing and treating esophageal cancer.