Optimization for an active fountain pen nanolithography device fabrication

Rui, Ming-Wu,Lee, Suk-Han,Kim, Hun-Mo 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.4

In this paper, a comprehensive consideration for the optimization of the Active Fountain Pen Nanolithography (AFPN) device is presented. The material and the dimensions of the device are chosen for the final fabrication. First, the effect of the capillary pressure is analyzed. In this device, the ink is directed into a channel by capillary pressure which is inversely proportional to the size of the channel. When the size of channel is very small, the capping layer of the channel will deflect and cavitations will probably occur in the chamber due to the capillary pressure. However, with the correct structural design and an adequate channel material, the cavitations and the deflection of the channel can be greatly reduced. With this in mind, we increased the size of the device for ease of the fabrication and to avoid cavitations. The pumping performance is simulated under the actual deflection of the membrane by FLUENT. The results show that the mass flow rate at the outlet is dependent on the amount of membrane deformation. As a final step, the state of the ink at the tip after it fills the device is simulated, with SiN showing the best performance in decreasing the amount of ink on the tip.

HMGB1 regulates autophagy through increasing transcriptional activities of JNK and ERK in human myeloid Leukemia cells

( Ming Yi Zhao ),( Ming Hua Yang ),( Liang Chun Yang ),( Yan Yu ),( Min Xie ),( Shan Zhu ),( Rui Kang ),( Dao Lin Tang ),( Zhi Gang Jiang ),( Wu Zhou Yuan ),( Xiu Shan Wu ),( Li Zhi Cao ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.9

HMGB1 is associated with human cancers and is an activator of autophagy which mediates chemotherapy resistance. We here show that the mRNA levels of HMGB1 are high in leukemia cells and it is involved in the progression of childhood chronic myeloid leukemia (CML). HMGB1 decreases the sensitivity of human myeloid leukemia cells K562 to anti-cancer drug induced death through up-regulating the autophagy pathway, which is confirmed by the observation with an increase in fusion of autophagosomes and autophagolysosomes. When overexpressing HMGB1, both mRNA levels of Beclin-1, VSP34 and UVRAG which are key genes involved in mammalian autophagy and protein levels of p-Bcl-2 and LC3-II are increased. Luciferase assays document that over-expression of HMGB1 increases the transcriptional activity of JNK and ERK, which may be silenced by siRNA. The results suggest that HMGB1 regulates JNK and ERK required for autophagy, which provides a potential drug target for therapeutic interventions in childhood CML. [BMB reports 2011; 44(9): 601-606]

An Interference Restraint Algorithm in OFDM-Based Cognitive Radio

Ming Rui Zou,Cheng Shi Zhao,Bin Shen,Ho Hwan Park,Kyung Sup Kwak 한국통신학회 2008 한국통신학회 학술대회 및 강연회 Vol.2008 No.4

Stanniocalcin-1 protects bovine intestinal epithelial cells from oxidative stress-induced damage

Li-ming Wu,Rui Guo,Lin Hui,Yong-gang Ye,Jing-mei Xiang,Chun-yun Wan,Miao Zou,Rui Ma,Xiao-zhuan Sun,Shi-jin Yang,Ding-zong Guo 대한수의학회 2014 JOURNAL OF VETERINARY SCIENCE Vol.15 No.4

Chronic enteritis can produce an excess of reactive oxygenspecies resulting in cellular damage. Stanniocalcin-1(STC-1)reportedly possesses anti-oxidative activity, the aim of thisstudy was to define more clearly the direct contribution ofSTC-1 to anti-oxidative stress in cattle. In this study, primaryintestinal epithelial cells (IECs) were exposed to hydrogenperoxide (H2O2) for different time intervals to mimic chronicenteritis-induced cellular damage. Prior to treatment with 200μM H2O2, the cells were transfected with a recombinantplasmid for 48 h to over-express STC-1. Acridine orange/ethidium bromide (AO/EB) double staining and trypan blueexclusion assays were then performed to measure cell viabilityand apoptosis of the cells, respectively. The expression of STC-1and apoptosis-related proteins in the cells was monitored byreal-time PCR and Western blotting. The results indicated thatboth STC-1 mRNA and protein expression levels positivelycorrelated with the duration of H2O2 treatment. H2O2 damagedthe bovine IECs in a time-dependent manner, and this effectwas attenuated by STC-1 over-expression. Furthermore, overexpressionof STC-1 up-regulated Bcl-2 protein expression andslightly down-regulated caspase-3 production in the damagedcells. Findings from this study suggested that STC-1 plays aprotective role in intestinal cells through an antioxidant mechanism.

Roadway Engineering Mechanical Properties and Roadway Structural Instability Mechanisms in Deep Wells

Xiang-Rui Meng,Rui Peng,Guang-Ming Zhao,Ying-Ming Li 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.5

We proposed a new classification method for stress-bearing structures in very-deep roadways. We conducted tests for roadwayengineeringmechanical properties, including rock mechanical tests and ground stress measurement of two caverns in very-deepwells. We suggested a classification method for stress-bearing structures based on shear stress. Tests revealed that rock strength in theshear direction was the lowest; the stress distributions of acoustic emission and hollow inclusion were highly similar. Based on theroadway-engineering mechanical properties of two caverns and numerical simulation and in-situ tests, the key bearing structureswere classified based on the concentrated shear stress. In deep caverns, shear stress was more concentrated on the softer surroundingrock, the key bearing structure areas, and the more seriously fractured surrounding rocks. Using the loose circle in-situ test, wecompared the classification method of the key bearing structures with other classification methods. The results revealed agreementwith the classification methods used for the key bearing structures. The deformation in-situ test showed that the strata convergence ofconcentrated shear stress areas developed quickly. Therefore, the phenomena of concentrated shear stress and the expanded range ofkey bearing structures are the structural instability mechanisms of deep roadways.

Cold hardiness characteristic of the overwintering pupae of fall webworm Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) in the northeast of China

Xiao-Rui Xu,Ming-Ming Zhu,Liang-Liang Li,Guang-Cai Zhang,Ye Zheng,Ting Li,Shou-Hui Sun 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.1

The fallwebworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), is an invasive and important pest in China. Understanding the physiological–biochemical characteristics of the overwintering pupae is essential for its cold tolerance and potential distribution in the northeast of China. Results indicated that the supercooling point (SCP) of H. cunea overwintering pupae varied significantly among Jilin city (43°N, 126°E), Jilin Province, Shenyang (41.8°N, 123.4°E), Liaoning Province and Yingkou (40.39°N, 122.13°E), Liaoning Province. The average SCP in Jilin was the lowest (−23.49 ± 0.46 °C) in those of three areas. The water content in overwintering pupae had a significant positive correlation with the SCP (R = 0.848,P = 0.03). Contents of alanine (ALA) (26.00%), lysine (LYS) (30.51%) and arginine (ARG) (22.88%) in the overwintering pupae's hemolymph were higher than others. During the overwintering, the fat content in pupae's bodies decreased gradually. Analysis of variance (ANOVA) indicated that the content of trehalose in the body of H. cunea was remarkably different (P= 0.007) month by month, with the maximum in March (2.88 mg·mL−1) and the minimum (0.40 mg·mL−1) in November. Pearson's correlation test indicated that SCP had a significant negative correlation with the SOD enzyme activity (R = −0.850; P = 0.008). Thermal hysteresis activity (THA) of hemolymph was 0.68°C and 0.7–0.8°C for H. cunea pupae and larva, respectively, using differential scanning calorimetry, which suggests that the H. cunea can improve their cold tolerance through producing antifreeze proteins. These results could help us to predict the distribution of the H. cunea in the northeast of China.

Effect of Viscosity on the Microformability of Bulk Amorphous Alloy in Supercooled Liquid Region

Ming Cheng,Shi-hong Zhang,Rui-xue Wang 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Previously published results have shown that viscosity greatly influences on the deformation behavior of the bulk amorphous alloy in supercooled liquid region during microforming process. And viscosity is proved to be a component of the evaluation index which indicating microformability. Based on the fluid flow theory and assumptions, bulk amorphous alloy can be regarded as the viscous materials with a certain viscosity. It is helpful to understand how the viscosity plays an important role in viscous materials with various viscosities by numerical simulation on the process. Analysis is carried out by linear state equation in FEM with other three materials, water, lubricant oil and polymer melt, whose viscosities are different obviously. The depths of the materials flow into the U-shaped groove during the microimprinting process are compared in this paper. The result shows that the deformation is quite different when surface tension effect is not considered in the case. With the lowest viscosity, water can reach the bottom of micro groove in a very short time. Lubricant oil and polymer melt slower than it. Moreover bulk amorphous alloys in supercooled liquid state just flow into the groove slightly. Among the alloys of different systems including Pd-, Mg- and Zr-based alloy, Pdbased alloy ranks largest in the depth. Mg-based alloy is the second. And Zr-based alloy is the third. Further more the rank order of the viscosities of the alloys is Pd-, Mg- and Zr-based. It agrees well with the results of calculation. Therefore viscosity plays an important role in the microforming of the bulk amorphous alloy in the supercooled liquid state.

The Investigation on Thermal Aging Characteristics of Oil-Paper Insulation in Bushing

Rui-jin Liao,En-de Hu,Li-jun Yang,Zuo-ming Xu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Bushing is the key link to connect outer and inner insulating systems and also the essential electric accessory in electric power system, especially in the high voltage engineering (AC 1000kV, DC 800kV). This paper presented the experimental research of thermal aging characteristic of oilpaper insulation used in bushing. A thermally accelerated aging experiment at 90℃ was performed. The bushing models containing five layers of paper were sealed into the aging vessels and further aged for 250 days. Then several important parameters associated with the aging were observed and evaluated. The results showed that the degree of polymerization (DP) of papers gradually decreased. The DP values of outermost layer and middle layer fit well into the second-order kinematic model and first-order kinematic model, respectively. Less deterioration speed of the inter-layer paper than outer layer was confirmed by the variation of DP. Hydrolysis was considered as the main cause to this phenomenon. In addition, the logarithm of the furfural concentrations in insulation oil was found to have good linear relationship with DP of papers. Interestingly, when the aging time is about 250 days and DP is 419, the aging process reaches an inflection point at which the DP approaches the leveling off degree of polymerization (LODP) value. Both tanδ and acid number of oils increased, while surface and volume resistivity of papers decreased. The obtained results demonstrated that thermal aging and moisture absorbed in papers brought great influence to the degradation of insulating paper, leading to rapid decrease of DP and increase of the tanδ . Thus, the bushing should be avoided from damp and real-time monitoring to the variation of tanδ and DP values of paper is an effective way to evaluate the insulation status of bushing.

Process and product innovarions in vertically differentiated markets with network externalities

Ming-qing Xing,Lai-sheng Wang,Rui-ting Zhang 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

We analyze product and process innovations in a vertically differentiated duopoly in market with externalities. Through assuming process innovation reduces marginal cost and product innovation improves product quality, we find that;(i) product and process innovations are complements (resp.substitutes) for the firm with low (resp. high) quality when the intensity of network externality is small; (ii) process innovation affects product innovation more intensely when exists network externality than not;(iii) network externality makes process R&D (resp. aggregate process R&D) outcome affected by the parameter of product innovation cost ;(iv) aggregate process R&D outcome in industry increases with network intensity; (v) the firm with higher initial efficiency invests more in process innovation and will obtain more demand and profit than the rival in equilibrium.

Stabilization Control for Spacecraft-manipulator System After Capturing Tumbling Target

Rui Chang,Qingxuan Jia,Ming Chu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

Non-cooperative target capturing is a great challenge for space robots among space tasks, because of the difficulty of target detumbling and base stability maintaining, which increasing the requirements for the control performances of the attitude control systems. In this paper, a contact force model combining an optimized Hertz’s model and the LuGre friction model is established, to estimate the contact force without additional sensors. And a novel control methodology for stabilization control of space robot based on an adaptive backstepping nonsingular fast integral terminal sliding mode control (ABNFITSMC) is developed, which significantly improve the convergence speed and satisfied the requirements of robustness of the complex system after capturing. First, the fully controllable dynamic model of the free-flying (no position control) space robot is established by using the Lagrange method. Then, the contact force between the end effector (gripper) and the target is analyzed by combining modified Hertz model and the LuGre friction model. Finally, a novel nonsingular fast integral terminal sliding mode (NFITSM) surface is proposed, so a finite-time convergence, non-singularity, fast transient response, precise trajectory tracking, robustness with uncertainties and disturbances is achieved. Then, an adaptive control law is used to approximate the upper bound value of the disturbance and uncertainties, and a backstepping control method is employed to guaranty the global asymptotic stability of the control system. The numerical simulation results show that the proposed algorithm can stable the attitude of the space robot in a quick limited time, and reduce the chattering significantly compared to the traditional sliding surface, the results demonstrates the superior performance of the proposed approach., and proves the feasibility of its application in non-cooperative target capturing task.