Manuscript numerical simulation on ultra-precision polishing of monocrystalline silicon by SPH method

Xiu Lei,Lv Gang,Xu Yan,Qiao Yang,Jiang Hai,Wang Xianwei,Ye Xia 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.7

Ultra-precision polishing is an important processing method for monocrystalline silicon, in order to improve the machining efficiency and obtain good machining quality, it is necessary to investigate the material removal process and process parameters of ultra-precision polishing. Smoothed particle hydrodynamics (SPH) is a meshless method with good self-adaptability, it can be used in the simulation of ultra-precision polishing which has high speed deformation characteristics. The calculation model and SPH analysis model of ultraprecision polishing are established according to the principle of ultra-precision polishing, SPH method is used to simulate and analyze ultra-precision polishing of the monocrystalline silicon. The material removal process of ultra-precision polishing is investigated, the effects of abrasive size and indentation depth on the equivalent plastic strain (PEEQ), Mises stress and the force of abrasive is investigated. The result is that, at the different time of ultra-precision polishing, the maximum PEEQ is different, but the difference is not obvious; the X direction force of the abrasive increases with the indentation depth; the size of abrasive has a great influence on the soft coefficient of stress state in ultra-precision polishing. According to the simulation results, it is possible to optimize the technological parameters of ultra-precision polishing, and provide the theoretical guidance for practical production.

H∞ Control with Multiple Packets Compensation Scheme for T-S Fuzzy Systems Subject to Cyber Attacks

Xiu-Ying Li,Bao-Jun Wang,Lei Zhang,Xiang-Hua Ma 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.1

This paper is concerned with the H∞ controller design problem for a class of network-based nonlinearsystems (NCSs) represented by the Takagi-Sugeno (T-S) fuzzy model. A multiple packets compensation schemeis developed which uses all the data stored in a finite memory buffer to compensate the negative effects of packetdropouts. This model contains the medium access constraint problem as a special case. The time-multiplexingmechanism may be used for such a case so that there are multiple packets arrive at the receiver side. By taking thestochastic cyber attacks into account, the desired controller in terms of linear matrix inequalities (LMIs) is designedby using fuzzy-rule-dependent Lyapunov method. The sufficient condition is obtained which makes the closed-loopsystem be asymptotically mean-square stable and achieve the prescribed H∞ disturbance-rejection-attenuation level. Finally, a mass-spring-damping system is given to show the effectiveness of the algorithm.

Esophageal Motility in the Supine and Upright Positions for Liquid and Solid Swallows Through High-resolution Manometry

( Xiu Jing Zhang ),( Xue Lian Xiang ),( Lei Tu ),( Xiao Ping Xie ),( Xiao Hua Hou ) 대한소화기기능성질환·운동학회 2013 Journal of Neurogastroenterology and Motility (JNM Vol.19 No.4

Background/Aims Most recent studies using high-resolution manometry were based on supine liquid swallows. This study was to evaluate the differences in esophageal motility for liquid and solid swallows in the upright and supine positions, and to determine the percentages of motility abnormalities in different states. Methods Twenty-four asymptomatic volunteers and 26 patients with gastroesophageal reflux disease underwent high-resolution manometry using a 36-channel manometry catheter. The peristalses of 10 water and 10 steamed bread swallows were recorded in both supine and upright positions. Integrated relaxation pressure, contractile front velocity, distal latency (DL) and the distal contractile integral (DCI) were investigated and comparisons between postures and boluses were analyzed. Abnormal peristalsis of patients was assessed applying the corresponding normative values. Results In total, 829 swallows from healthy volunteers and 959 swallows from patients were included. (1) The upright position provided lower integrated relaxation pressure, shorter DL and weaker DCI than the supine position. (2) In the comparison of liquid swallows, the mean for contractile front velocity was obviously reduced while DL and DCI were increased in solid swallows. (3) The supine position detected more hypotensive peristalsis than the upright position. The upright position provided more rapid and premature contraction than the supine position but there was no statistically significant difference. Conclusions Supine solid swallows occur with more hypotensive peristalsis. Analysis should be based on normative values from the corresponding posture and bolus. (J Neurogastroenterol Motil 2013;19:467-472)

Fault Tolerant Control for an Unmanned Surface Vessel Based on Integral Sliding Mode State Feedback Control

Xiu-Ning Yu,Li-Ying Hao,Xiao-Lei Wang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

In the complex ocean environment, the thruster faults may affect the stability of unmanned surface vessel (USV). So it is really important to study the problem of USV fault tolerant control. Under the framework of integral sliding mode technology, this work presents a fault tolerant control problem for USV. First, a comprehensive thruster fault model with total faults, partial faults, hard-over faults, bias faults, and time-varying stuck faults, is established. Then, an integral sliding mode surface and sliding mode controller with fault estimation are designed. Through LMI technology and Lyapunov stability theory, the stability of sliding mode has been proved. Compared with the existing results, the oscillation amplitudes of yaw angle and yaw velocity can be suppressed from the every beginning. Finally, simulation results demonstrate that the proposed integral sliding mode fault tolerant control algorithm is effective.

Acid-free epoxidation of soybean oil with hydrogen peroxide to epoxidized soybean oil over titanium silicalite-1 zeolite supported cadmium catalysts

Lei Cai,Chao CHEN,Wenjun Wang,Xiu Gao,Xiaoyan Kuang,Yan Jiang,Liang Li,Guoqiang Wu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Titanium silicalite-1 (TS-1) zeolite was successfully synthesized by hydrothermal method in the presenceof the tetrapropylammonium hydroxide (TPAOH) template, and a series of TS-1 supported cadmium withdifferent Cd loading (xCd/TS-1) catalysts were carefully prepared to produce epoxidized soybean oil(ESO) through the acid-free catalytic epoxidation of soybean oil (SO) with H2O2. These catalysts were fullycharacterized using various modern techniques and further evaluated systematically in this epoxidationreaction to understand the relationship between catalytic activity and structure of active components. The results show that the highly dispersed Cd species are introduced on the TS-1 support withoutaffecting the coordination environment of tetrahedral Ti (framework Ti). Furthermore, the Cd species arecoordinated with tetrahedral Ti species via O atom resulting in the weakness of the Ti–O bonds and facileattack of the Ti–O bonds by alcohol and H2O2, which can easily form thefive-membered intermediate andpromote the SO epoxidation process. Furthermore, the deactivation and regeneration behaviors of 2%Cd/TS-1 catalyst in SO epoxidation were also investigated, which reveal that the catalyst deactivation of cokedeposition is due to the strong adsorption of the catalysts and SO molecules. But the spent 2%Cd/TS-1 canbe completely regenerated by calcination method.

Clinical Model for Predicting Hepatocellular Carcinomas in Patients with Post-Sustained Virologic Responses of Chronic Hepatitis C: A Case Control Study

( Qing-lei Zeng ),( Bing Li ),( Xue-xiu Zhang ),( Yan Chen ),( Yan-ling Fu ),( Jun Lv ),( Yan-min Liu ),( Zu-jiang Yu ) 대한소화기학회 2016 Gut and Liver Vol.10 No.6

Background/Aims: No clinical model exists to predict the occurrence of hepatocellular carcinoma in sustained virologic response-achieving (HCC after SVR) patients with chronic hepatitis C (CHC). Methods: We performed a case-control study using a clinical database to research the risk factors for HCC after SVR. A predictive model based on risk factors was established, and the area under the receiver operating characteristic curve (AUC) was calculated. Results: In the multivariate model, an initial diagnosis of compensated cirrhosis and post-SVR albumin reductions of 1 g/L were associated with 21.7-fold (95% CI, 4.2 to 112.3; p< 0.001) and 1.3-fold (95% CI, 1.1 to 1.7; p=0.004) increases in the risk of HCC after SVR, respectively. A predictive model based on an initial diagnosis of compensated cirrhosis (yes, +1; no, 0) and post- SVR albumin ≤36.0 g/L (yes, +1; not, 0) predicted the occurrence of HCC after SVR with a cutoff value of >0, an AUC of 0.880, a sensitivity of 0.833, a specificity of 0.896, and a negative predictive value of 0.956. Conclusions: An initial diagnosis of compensated cirrhosis combined with a post-SVR albumin value of ≤36.0 g/L predicts the occurrence of HCC after SVR in patients with CHC. (Gut Liver 2016;10:955-961)

Clinical Risk Factor Analysis for Breast Cancer: 568,000 Subjects Undergoing Breast Cancer Screening in Beijing, 2009

Pan, Lei,Han, Li-Li,Tao, Li-Xin,Zhou, Tao,Li, Xia,Gao, Qi,Wu, Li-Juan,Luo, Yan-Xia,Ding, Hui,Guo, Xiu-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Objectives: Although there are many reports about the risk of breast cancer, few have reported clinical factors including history of breast-related or other diseases that affect the prevalence of breast cancer. This study explores these risk factors for breast cancer cases reported in Beijing in 2009. Materials and Methods: Data were derived from a Beijing breast cancer screening performed in 2009, of 568,000 women, from 16 districts of Beijing, all aged between 40 and 60 years. In this study, multilevel statistical modeling was used to identify clinical factors that affect the prevalence of breast cancer and to provide more reliable evidence for clinical diagnostics by using screening data. Results and Conclusion: Those women who had organ transplants, compared with those with none, were associated with breast cancer with an odds ratio (OR)=65.352 [95% confidence interval (CI): 8.488-503.165] and those with solid breast mass compared with none had OR=1.384 (95% CI: 1.022-1.873). Malignant tendency was strongly associated with increased risk of breast cancer, OR=207.999(95% CI: 151.950-284.721). The risk of breast cancer increased with age, $OR_1$=2.759 (95% CI: 1.837-4.144, 56-60 vs. 40-45), $OR_2$=2.047 (95% CI: 1.394-3.077, 51-55 vs. 40-45), $OR_3$=1.668 (95% CI: 1.145-2.431). Normal results of B ultrasonic examination show a lower risk among participants, OR= 0.136 (95% CI: 0.085-0.218). Those women with ductal papilloma compared with none were associated with breast cancer, OR=6.524 (95% CI: 1.871-22.746). Therefore, this study suggests that clinical doctors should pay attention to these high-risk factors.

Lack of Prognostic Value of Human Epidermal Growth Factor- Like Receptor 2 Status in Inflammatory Breast Cancer (IBC): a Meta-analysis

Li, Xiu-Juan,Zha, Quan-Bin,Xu, Xin-Yu,Xia, Lei,Zhang, Zhe,Ren, Zhao-Jun,Tang, Jin-Hai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.22

Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer which is more likely to be her-2/neu amplified. While the her-2/neu status has been utilised to predict prognosis, the published data are inconsistent. The present meta-analysis was conducted to determine whether the her-2/neu status predicts outcomes. Papers were selected from the PubMed database based on defined inclusion and exclusion criteria. Parameters such as total patients, follow-up time and outcome statistics (i.e. overall survival (OS), relapse-free survival (RFS) were collected. The analysis included 6 studies with 2,838 IBC patients. The summary hazards ratio (HR) estimating the association of OS with HER-2-positive disease was 0.96 (95% confidence interval (95%CI: 0.85-1.10)), with similar findings for RFS (HR=0.81, 95%CI: 0.61-1.09). No obvious statistical heterogeneity was detected. This meta-analysis suggests that HER-2-positive status is not an independent adverse prognostic factor for survival among IBC patient cases.

Microstructure and Mechanical Properties of Laser Welded Joints of DZ125L and IN718 Nickel Base Superalloys

Taosha Liang,Lei Wang,Yang Liu,Xiu Song 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.3

The microstructure and mechanical properties of the laser welded joint of DZ125L and IN718 nickel base superalloys wereinvestigated. The results show that the fusion zone (FZ) mainly consists of fi ne dendrite structure with fi ne γ′, Laves phasesand MC carbides inhomogeneously distributed. The high welding temperature induces the partial dissolution of γ′ in theheat-aff ected zone (HAZ) of DZ125L and liquation of grain boundaries in both of the HAZs. After post-weld heat treatment(PWHT), fi ne γ″ and γ′ phases precipitate in the FZ, IN718 HAZ and IN718 base metal (BM), and fi ne γ′ precipitate in theγ channel of the HAZ and BM of DZ125L. With tensile testing, the joints after PWHT show higher strengths than that ofthe weaker DZ125L alloy. Plastic deformation mainly concentrates in the weaker DZ125L and the joint fi nally fails in theDZ125L BM.

A Correlation Research of Moral behavior in Physical Education Learning Process of College Students in Shanghai

( Si Man Lei ),( Yan Xiu Cai ),( Mei Jun Teng ),( Chen Song Wang ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Purpose: The study was to explore the relationship between physical education, moral education and moral behaviors, and the difference of moral behaviors among college students in Shanghai. Method: The targeted voluntary participants were 399 college students in Shanghai. Data were collected through administering self-report scale of Moral behavior in Physical Education was used, which with Cronbach`s alpha is .983. It is designed to investigate the relationship between individual`s demographic background (age, gender, grade, self-perceived academic performance, socioeconomic status and self-esteem), participating sports types, and the seven moral behaviors (self-directed learning, motivation of sport participation, individual goal orientation, responsibility, respect, leadership and caring). For group differences, correlation study and regression investigation were interpreted through data analysis in SPSS 20.0. Result: 1) It can be found having no time is the main reason for not participating in extracurricular physical activities. 2) The moral education, physical and mental health, compliance and equality, integrity and diligence and self-improvement and cooperation were correlated significantly. 3) There was gender difference on active participation. 4) Physical and mental health, active participation, self-orientation, leadership were positively correlated with the overall moral behavior scale. Conclusion: College students who participate more in exercise have better performance on moral behavior. Therefore college students should do more exercises. Considering that integrity and diligence, self-improvement and cooperation, and offering help that sport club participants scored higher than non-participants, we should encourage college students to participant in more sport clubs. Changing traditional teaching model, searching for new methods in improving moral education and further promoting the integration of physical and moral education is needed. A relevant curriculum could be established in future teaching program.