Experiment research on grind-hardening of AISI5140 steel based on thermal compensation

Xiangming Huang,Yinghui Ren,Bo Zheng,Zhaohui Deng 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.8

The grind-hardening process utilizes the heat generated to induce martensitic phase transformation. However, the maximum achievable harden layer depth is limited due to high grinding forces, and the tensile residual stress appears on the ground surface in the grindhardening process. This paper proposes a new grind-hardening technology using thermal compensation. The workpiece of AISI5140 steel is preheated by electric resistance heating, and ground under the condition of the workpiece temperature 25°C, 120°C, 180°C and 240°C. The grinding force, harden layer depth and surface quality including residual stress on ground surface, surface roughness and micro-hardness are investigated. The experimental results show that a deep harden layer with a fine grain martensite can be obtained with the thermal compensation. The ground workpiece surface produces a certain compressive residual stress, and the residual compressive stress value increases with preheating temperature. As the preheating temperature increases, grinding force slightly decreases, while there is slightly increment of surface roughness. Compared with the conventional grind-hardening process, both the harden layer depth and residual stress distribution are significantly improved.

A constitutive model for fiber-reinforced extrudable fresh cementitious paste

Xiangming Zhou,Zongjin Li 사단법인 한국계산역학회 2011 Computers and Concrete, An International Journal Vol.8 No.4

In this paper, time-continuous constitutive equations for strain rate-dependent materials are presented first, among which those for the overstress and the consistency viscoplastic models are considered. By allowing the stress states to be outside the yield surface, the overstress viscoplastic model directly defines the flow rule for viscoplastic strain rate. In comparison, a rate-dependent yield surface is defined in the consistency viscoplastic model, so that the standard Kuhn-Tucker loading/unloading condition still remains true for rate-dependent plasticity. Based on the formulation of the consistency viscoplasticity, a computational elasto-viscoplastic constitutive model is proposed for the short fiber-reinforced fresh cementitious paste for extrusion purpose. The proposed constitutive model adopts the von-Mises yield criterion, the associated flow rule and nonlinear strain rate-hardening law. It is found that the predicted flow stresses of the extrudable fresh cementitious paste agree well with experimental results. The rate-form constitutive equations are then integrated into an incremental formulation, which is implemented into a numerical framework based on ANSYS/LS-DYNA finite element code. Then, a series of upsetting and ram extrusion processes are simulated. It is found that the predicted forming load-time data are in good agreement with experimental results, suggesting that the proposed constitutive model could describe the elasto-viscoplastic behavior of the short fiber-reinforced extrudable fresh cementitious paste.

Experimental study on white layers in high-speed grinding of AISI52100 hardened steel

Xiangming Huang,Yinghui Ren,Zhixiong Zhou,Hang Xiao 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.3

Ground white layer structure is an untempered martensitic due to grinding heat and plastic deformation. Many researchers have studiedthe formation of white layers at low grinding speed. However, few studies were found on white layer at high grinding speed. Therefore,to minimize white layer, it would be very useful to know the formation of white layer in the high-speed grinding. We performed grindingexperiments using hardened AISI52100 steel with cubic boron nitride (CBN). Grinding force and grinding temperature were onlinemeasured during grinding process. Surface roughness, residual stress and white layer were also examined, respectively. The influence ofgrinding wheel speed on grinding force and surface integrity was analyzed. Formation of white layer was also studied. Experimentalresults show that grinding force and plastic deformation decrease significantly at higher grinding speed. Meanwhile, white layer depthand residual stress value increase with the grinding wheel speed, and residual stress is well correlated with ground white layer depth. White layer during high-speed grinding process results from phase transformation due to grinding heat and rapid cooling, while the plasticdeformation may be ignored for the ground white layer.

Hybrid Polymer-Metal Microcoils for Power Transfer in Nanorobotics

Xiangming Cheng,PREM PRABHAKARAN 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.2

GTP Binding Is Required for SEPT12 to Form Filaments and to Interact with SEPT11

Xiangming Ding,Wenbo Yu,Ming Liu,ShuQing Shen,Fang Chen,Lihuan Cao,Bo Wan,Long Yu 한국분자세포생물학회 2008 Molecules and cells Vol.25 No.3

Septins are a family of filament-forming GTP-binding proteins involved in a variety of cellular process such as cytokinesis, exocytosis, and membrane dynamics. Here we report the biochemical and immunocytochemical characterization of a recently identified mammalian septin, SEPT12. SEPT12 binds GTP in vitro, and a mutation (Gly56 to Asn) in the GTPbinding motif abolished binding. Immunocytochemical analysis revealed that wild-type SEPT12 formed filamentous structures when transiently expressed in Hela cells whereas SEPT12G56A generated large aggregates. In addition, wild-type SEPT12 failed to form filaments when coexpressed with SEPT12G56A. We also observed that GTP-binding by SEPT12 is required for interaction with SEPT11 but not with itself.

Fasting Blood Glucose, Cholesterol, and Risk of Primary Liver Cancer: The Kailuan Study

Xiangming Ma,Haozhe Cui,Miaomiao Sun,Qian Liu,Xining Liu,Guangjian Li,Yaochen Wei,Qingjiang Fu,Siqing Liu,Liying Cao 대한암학회 2021 Cancer Research and Treatment Vol.53 No.4

Purpose The influence of fasting blood glucose (FBG) and cholesterolemia primary liver cancer (PLC) in China was analyzed via a large prospective cohort study based on a community population, and the combined effects between them were investigated. Materials and Methods Overall, 98,936 staff from the Kailuan Group who participated in and finished physical examinations bet-ween 2006 and 2007 were included in the cohort study. Their medical information was collected and they were followed up after examination. The correlations of serum FBG or total cholesterol (TC) with PLC were analyzed. Then, we categorized all staff into four groups: normal FBG/non-hypocholesterolemia, normal FBG/hypocholesterolemia, elevated FBG/non-hypocholesterolemia, elevated FBG/hypocholesterolemia, and normal FBG/non-hypocholesterolemia was used as a control group. The combined effects of elevated FBG and hypocholesterolemia with PLC were analyzed using the Age-scale Cox proportional hazard regression model. Results During 1,134,843.68 person-years follow-up, a total of 388 PLC cases occurred. We found the elevated FBG and hypocholesterolemia increase the risk for PLC, respectively. Compared with the non-hypocholesterolemia/normal FBG group, the risk of PLC was significantly increased in the non-hypocholesterolemia/elevated FBG group (hazard artio [HR], 1.19; 95% confidence interval [CI], 0.88 to 1.62) and hypocholesterolemia/normal FBG group (HR, 1.53; 95% CI, 1.19 to 1.97), and in the hypocholesterolemia/elevated FBG group (HR, 3.16; 95% CI, 2.13 to 4.69). And, a significant interaction effect was found of FBG and TC on PLC. All results were independent from the influence of liver disease. Conclusion Elevated serum FBG and hypocholesterolemia are risk factors for PLC, especially when combined. Thus, for the prevention and treatment of PLC, serum FBG and TC levels should be investigated.

SEPT12 Interacts with SEPT6 and This Interaction Alters the Filament Structure of SEPT6 in Hela Cells

Ding, Xiangming,Yu, Wenbo,Liu, Ming,Shen, Suqin,Chen, Fang,Wan, Bo,Yu, Long Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

Septins are a family of conserved cytoskeletal GTPase forming heteropolymeric filamentous structure in interphase cells, however, the mechanism of assembly are largely unknown. Here we described the characterization of SEPT12, sharing closest homology to SEPT3 and SEPT9. It was revealed that subcelluar localization of SEPT12 varied at interphase and mitotic phase. While SEPT12 formed filamentous structures at interphase, it was localized to the central spindle and to midbody during anaphase and cytokinesis, respectively. In addition, we found that SEPT12 can interact with SEPT6 in vitro and in vivo, and this interaction was independent of the coiled coil domain of SEPT6. Further, co-expression of SEPT12 altered the filamentous structure of SEPT6 in Hela cells. Therefore, our result showed that the interaction between different septins may affect the septin filament structure.

應用孟五於今日台灣海運倫理領導指標之建構

孟祥民(MENG xiangming),丁益軍(DING yijun),彭海豔(PENG, haiyan),李潔(LI jie) 동북아시아문화학회 2013 동북아시아문화학회 국제학술대회 발표자료집 Vol.2013 No.5

Effect of molecular weight of regenerated silk fibroin on silk-based spheres for drug delivery

Zengkai Wang,Xiangming Li,Yanhua Cui,Kai Cheng,Mingdong Dong,Lei Liu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.10

Silk fibroin presents a good advantage as a drug carrier for drug delivery, due to the excellent biocompatibility, biodegradability and tunable drug loading and release properties. In this work, we constructed silk spheres by phase separation of the regenerated silk fibroin (RSF) solutions with different MW and polyvinyl alcohol; and it was revealed that MW of RSF can affect the structure, size, surface potential and drug loading and release efficiency of silk spheres. Silk spheres prepared from high MW of RSF were found to load more macromolecular drug with negative charge compared to middle and low MW of RSF. However, for the positive charge and low MW drug, the silk spheres prepared from low MW of RSF could present a high loading efficiency compared to other carriers. Finally, a positive drug with low MW, streptomycin was encapsulated in silk spheres prepared from low MW of RSF, and displayed a long bactericidal and bacteriostatic effect compared to bared streptomycin solution. The results obtained provide guidelines for the modification and options of drug transport vehicles for more efficient drug delivery and utilization through a simple, rapidly constructed, applicable and low-cost drug carrier.

3D Markov chain based multi-priority path selection in the heterogeneous Internet of Things

( Huan Wu ),( Xiangming Wen ),( Zhaoming Lu ),( Yao Nie ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.11

Internet of Things (IoT) based sensor networks have gained unprecedented popularity in recent years. With the exponential explosion of the objects (sensors and mobiles), the bandwidth and the speed of data transmission are dwarfed by the anticipated emergence of IoT. In this paper, we propose a novel heterogeneous IoT model integrated the power line communication (PLC) and WiFi network to increase the network capacity and cope with the rapid growth of the objects. We firstly propose the mean transmission delay calculation algorithm based the 3D Markov chain according to the multi-priority of the objects. Then, the attractor selection algorithm, which is based on the adaptive behavior of the biological system, is exploited. The combined the 3D Markov chain and the attractor selection model, named MASM, can select the optimal path adaptively in the heterogeneous IoT according to the environment. Furthermore, we verify that the MASM improves the transmission efficiency and reduce the transmission delay effectively. The simulation results show that the MASM is stable to changes in the environment and more applicable for the heterogeneous IoT, compared with the other algorithms.