Experiment Study on Efficient Flank Milling of Ti6AL4V Thin-walled Components

Yanyan Guo,Huayan Zhong,Wantao He,Guangfu Tao 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.7

Flank milling is a method of line contact machining and also is an important method in machining aerospace structures components, turbine blades and so on. In this paper, flank milling of Ti6AL4V is conducted with carbide tools on CNC machining center. First, acquired cutting force signals are analyzed in time domain and frequency domain based on Matlab software to obtain the distribution of cutting force energy. Second, the flank milling force experimental formulas are established by means of regression analysis. Finally, the influence of cutting parameters such as feed per tooth, the axial depth of cut, cutting width and cutting speed on cutting force is studied. The curves between cutting parameters and cutting force are obtained by analyzing the flank milling experiment. This research has certain guiding significance in selecting cutting parameters for flank machining Ti6AL4V.

BERGMAN TYPE OPERATORS ON SOME GENERALIZED CARTAN-HARTOGS DOMAINS

He, Le,Tang, Yanyan,Tu, Zhenhan Korean Mathematical Society 2021 대한수학회지 Vol.58 No.6

For µ = (µ₁, …, µ_t) (µ_j > 0), ξ = (z₁, …, z_t, w) ∈ ℂ^n₁ × … × ℂ^n_t × ℂ^m, define $${\Omega}({\mu},t)=\{{\xi}{\in}\mathbb{B}_{n_1}{\times}{\cdots}{\times}\mathbb{B}_{n_t}{\times}\mathbb{C}^m:{\parallel}w{\parallel}^2<C({\chi},{\mu})\prod_{j=1}^{t}(1-{\parallel}z_j{\parallel}^2)^{{\mu}_j}\},$$ where $\mathbb{B}_{n_j}$ is the unit ball in ℂ^n_j (1 ≤ j ≤ t), C(χ, µ) is a constant only depending on χ = (n₁, …, n_t) and µ = (µ₁, …, µ_t), which is a special type of generalized Cartan-Hartogs domain. We will give some sufficient and necessary conditions for the boundedness of some type of operators on L^p(Ω(µ, t), ω) (the weighted L^p space of Ω(µ, t) with weight ω, 1 < p < ∞). This result generalizes the works from certain classes of generalized complex ellipsoids to the generalized Cartan-Hartogs domain Ω(µ, t).

Construction and Analysis of Food-Grade Lactobacillus kefiranofaciens β-Galactosidase Overexpression System

( Xi He ),( Mingjian Luan ),( Ning Han ),( Ting Wang ),( Xiangzhong Zhao ),( Yanyan Yao ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.4

Lactobacillus kefiranofaciens contains two types of β-galactosidase, LacLM and LacZ, belonging to different glycoside hydrolase families. The difference in function between them has been unclear so far for practical application. In this study, LacLM and LacZ from L. kefiranofaciens ATCC51647 were cloned into constitutive lactobacillal expression vector pMG36e, respectively. Furtherly, pMG36nlacs was constructed from pMG36e-lacs by replacing erythromycin with nisin as selective marker for food-grade expressing systems in Lactobacillus plantarum WCFS1, designated recombinant LacLM and LacZ respectively. The results from hydrolysis of o-nitrophenyl-β-galactopyranoside (ONPG) showed that the β-galactosidases activity of the recombinant LacLM and LacZ was 1460% and 670% higher than that of the original L. kefiranofaciens. Moreover, the lactose hydrolytic activity of recombinant LacLM was higher than that of LacZ in milk. Nevertheless, compare to LacZ, in 25% lactose solution the galacto-oligosaccharides (GOS) production of recombinant LacLM was lower. Therefore, two β-galactopyranosides could play different roles in carbohydrate metabolism of L. kefiranofaciens. In addition, the maximal growth rate of two recombinant strains were evaluated with different temperature level and nisin concentration in fermentation assay for practical purpose. The results displayed that 37oC and 20-40 U/ml nisin were the optimal fermentation conditions for the growth of recombinant β-galactosidase strains. Altogether the food-grade Expression system of recombinant β-galactosidase was feasible for applications in the food and dairy industry.

An Improved B-Spline Fitting Method with Arc-Length Parameterization, G2-Continuous Blending, and Quality Refinement

Kang Min,Yanyan Sun,Chen-Han Lee,Pengcheng Hu,Shanshan He 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.11

In computer numerical control machining, tool paths are typically represented with piecewise linear segments (GO1s), which lack G1 and G2 continuity and cause fluctuation of feed rate and acceleration. To improve the continuity of tool paths, some method, e.g., B-spline tool path fitting, is preferred. However, none of the currently B-spline fitting method satisfies all tool-path fitting requirements of arc-length parameterization, G2 continuity and smoothness across the whole path. The aim of this research is to derive an industrial-strength method for B-spline tool path fitting, satisfying all of the named requirements. The improvements cover the arc-length based parameterization, G2 continuity as well as numerically measure to improve the quality of B-spline tool paths. To achieve arc-length parameterization, a preliminary fitting is added to evaluate arc-length and guide the parameterization (i.e., knot vector assignment); for joint G2-continuity, a five-control-point B-spline which satisfies chord error and shape-preserving constraints is constructed to blend adjacent B-splines; and a method based on the Hausdorff distance between the fitted B-splines and the original polylines is used to evaluate the fitting quality, and an additional refinement procedure is employed when the evaluation finds any disqualification. Simulation and experiment results prove that the proposed methods are effective.

Management strategy for Spodoptera frugiperda (Lepidoptera:Noctuidae) in mountain maize planting areas in China

Yao Yao,He Yanyan,Zhang Lilan,Wang Kun,Li Bin,Du Guangzu,Zhu Chunyue,Yi Xiaocui,Liu Yiyi,Zi Shengjiang,Chen Bin,Xiao Guanli 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is a major maize pest worldwide and has caused huge economic loss. To explore the control tactics of S. frugiperda in mountain maize planting fields, studies were performed in China from 2020 to 2021 for screening the S. frugiperda-resistant maize variety, seed coating agents, chemical insecticides, and biological agents. The results showed that 75 g/hm 2 Emamectin benzoate had better controlling efficacy (with a control efficacy of 91.05% at 1d) than other chemicals, so it was recommended in the high incidence period of pests. Compared with other seed coating treatments, 50% Lumi ngwei TM625FS (with a control efficacy of 76.19% at 10d) was the best seed coating against S. frugiperda. The biological control “Telenomus remus + Picromerus lewisi” and “T. remus + Eocanthecona furcellata” had good control efficacy on S. frugiperda with 76.01%, 64.10% at 20d, respectively. Additionally, there were lower numbers of S. frugiperda in maize variety GuiDan6, BaoYu9, and YanBaiYu8. In summary, this research rec ommended four effective pest management strategies (GuiDan6-resistant maize variety, 50% Lumingwei TM625FS-seed coating agents, 5% emamectin benzoate-chemical pesticide, and “T. remus + P. lewisi”-biological control) in mountain maize planting fields. The study provided effective control strategies for

Infection of tomato by Tomato Yellow Leaf Curl Virus alters the foraging behavior and parasitism of the parasitoid Encarsia formosa on Bemisia tabaci

Xin Liu,Yanyan He,Wen Xie,Qingjun Wu,Youjun Zhang,Yong Liu,Shaoli Wang 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.2

Encarsia formosa Gahan is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies including Bemisia tabaci (Gennadius). Bemisia tabaci biotypes B and Q are two most invasive species that greatly reduce crop yields in China by feeding on plant sap and by transmitting Tomato Yellow Leaf Curl Virus (TYLCV). The effects of TYLCV infection of tomato on E. formosa foraging on B. tabaci B and Q are unknown. In Y-tube olfactometer assays in the present study, E. formosa significantly preferred TYLCVinfected tomato plants over TYLCV-free plants. The wasp females also significantly preferred TYLCV-infected tomato plants infested with 3rd-instar nymphs of B. tabaci biotype Q over TYLCV-free plants with biotype Q nymphs. However, no significant differences were observed when B. tabaci biotype B was infested on tomato plants. The oviposition bioassays confirmed that TYLCV infection on tomato plants resulted in the recruitment of parasitoids. These results indicate that TYLCV-infection of tomato increase the foraging of E. formosa on B. tabaci, as differs on the B and Q biotypes.

Functional roles and mechanisms of ginsenosides from Panax ginseng in atherosclerosis

Qianqian Xue,Ningning He,Zhibin Wang,Xiuxiu Fu,Lynn Htet Htet Aung,Yan Liu,Min Li,Jae Youl Cho,Yanyan Yang,Tao Yu 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.1

Atherosclerosis (AS) is a leading cause of cardiovascular diseases (CVDs) and it results in a high rate of death worldwide, with an increased prevalence with age despite advances in lifestyle management and drug therapy. Atherosclerosis is a chronic progressive inflammatory process, and it mainly presents with lipid accumulation, foam cell proliferation, inflammatory response, atherosclerotic plaque formation and rupture, thrombosis, and vascular calcification. Therefore, there is a great need for reliable therapeutic drugs or remedies to cure or alleviate atherosclerosis and reduce the societal burden. Ginsenosides are natural steroid glycosides and triterpene saponins obtained mainly from the plant ginseng. Several recent studies have reported that ginsenosides have a variety of pharmacological activities against several diseases including inflammation, cancer and cardiovascular diseases. This review focuses on describing the different pharmacological functions and underlying mechanisms of various active ginsenosides (Rb1,-Rd, -F, -Rg1, -Rg2, and -Rg3, and compound K) for atherosclerosis, which could provide useful insights for developing novel and effective anti-cardiovascular drugs.

Rapid Detection of Vibrio parahaemolyticus Strains and Virulent Factors by Loop-mediated Isothermal Amplification Assays

Xihong Zhao,Li Wang,Jin Chu,Yanyan Li,Yanmei Li,Lin Li,Mark E. Shirtliff,Xiaowei He,Yao Liu,Jihua Wang,Liansheng Yang,Zhenbo Xu 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.5

A loop-mediated isothermal amplification (LAMP) method for rapid detection of the foodborne Vibrio parahaemolyticus strains and related virulent factors had been developed and evaluated in this study. Six primers, including outer primers, inner primers, and loop primers, were specially designed for recognizing 8 distinct sequences on 3 target genes, which were tlh, tdh, and trh. The detection limits were found to be 100, 100 fg, and 1 pg DNA/tube for tlh, tdh, and trh, respectively. Application of LAMP assays were performed on 368 foodborne V. parahaemolyticus strains, the sensitivities of LAMP assays for the tlh, tdh, and trh were 100, 95.6, and 96.4%, and the negative predictive values (NPV) were 100, 84.7, and 93.1%, respectively; with a 100% specificity and positive predictive value (PPV) for all 3 target genes.

Adaptive Event-triggered Fault Detection Filter for a Class of Conic-type Nonlinear Hidden Semi-Markov Jump Systems

Kaixuan Chen,Xiang Zhang,Shuping He,Kaibo Shi,Yanyan Yin 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

This paper investigates the filtering-based asynchronous fault detection problem for a class of continuoustime conic-type nonlinear semi-Markov jump systems via adaptive event-triggered approach. Firstly, the asynchrony of filter modes and system modes are described by a hidden semi-Markov model. Secondly, an adaptive eventtriggered scheme is developed to reduce the transmissions from the system to the designed filter and improve the efficiency of data transmission. Then, by applying linear matrix inequalities techniques, sufficient conditions are obtained to ensure the stochastic stability and H∞ performance of the fault detection system. Finally, a tunnel diode circuit model is given to confirm the accuracy and effectiveness of the designed approach.

A Gel-like Comb Micro-Block Hydrophobic Associating Polymer: Synthesis, Solution Property and the Sol-Gel Transition at Semi-Dilute Region

Wanfen Pu,Feng Jiang,Bing Wei,Yanli Tang,Yanyan He 한국고분자학회 2017 Macromolecular Research Vol.25 No.2

The gel-like comb micro block hydrophobic associating polymer (CBHAP) was synthesized by mixed micellar polymerization. The chemical structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR). The rheological properties of CBHAP in fresh water and saline water at semi-dilute region were investigated. The experimental results show that, because of the intermolecular forces, shear thickening phenomenon can be observed obviously in brine solution and the Newtonian viscosity plateau could be observed clearly before 40 s-1. When the concentration reaches 3,000 mg/L, the G’ and G’’ becomes stable, indicating that CBHAP experiences the sol-gel transition after 3,000 mg/L. However, the curl structure is formed by adding salt, resulting in a higher concentration of the sol-gel transition than that in fresh water. Once the curl structure is destroyed by shearing or stretching, the intermolecular forces will take into effect and complete the sol-gel transition at semi-dilute region.