Nonlinear-Dynamic-Analysis Based Fuzzy PID Control Approach for Complex Hydraulic Driving Process

Zheng-Qiang Zhu,Xin-Jiang Lu,Jie Lei,Ming-Hui Huang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.7

The strong nonlinearity of the hydraulic driving process for forging makes it difficult to achieve accurate control. In this paper, we propose a nonlinear-dynamic-analysis based Fuzzy PID control approach for this complex process. Unlike the existing control methods that are designed specifically for a given work piece, this proposed control method can be effectively used in the forging of different work pieces. A model of the closed-loop forging system is first derived and a solving method is then developed in order to find the model solution. Using this model solution, the dynamics of the closed-loop forging system is further estimated and the conditions for stability, vibration, and creep, as well as the relationships between the controller parameters and the constraints are also derived. These derived dynamic characteristics, conditions and relationships for different work pieces are further integrated and used to design the controller. Through the use of experiments and simulations on a practical forging system, the effectiveness of all of these analytical results and the designed controller is finally demonstrated.

Percutaneous Radiofrequency Ablation Guided by Contrast-enhanced Ultrasound in Treatment of Metastatic Hepatocellular Carcinoma after Liver Transplantation

Dai, Xin,Zhao, Hong-Qiang,Liu, Run-Hao,Xu, Chang-Tao,Zheng, Fang,Yu, Li-Bao,Li, Wei-Min Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

This study evaluated the advantages and applications of contrast-enhanced ultrasound (CEUS)-supported percutaneous radiofrequency ablation (RFA) in the treatment of metastatic hepatocellular carcinoma after liver transplantation, based on clinical details. CEUS-supported percutaneous RFA was adopted to treat 12 patients with hepatic metastatic carcinomas after liver transplantation. The diameters of the metastatic carcinomas varied from 1 cm to 5 cm, and the foci were discovered after 3 months to 12 months. Each focus was diagnosed and localised by CEUS for RFA once or twice. Curative effects were evaluated by CEUS or contrast-enhanced CT after the treatment. The re-examination results at 2 weeks post-treatment showed that the foci of 11 patients were ablated completely, whereas one patient with the largest focus required retreatment by RFA because of a partial residue. No local recurrence was found one month later in the re-examination. CEUS-supported percutaneous RFA in the treatment of hepatic metastatic carcinoma after liver transplantation has the advantages of accurate localisation, good efficacy, easy operation, and minimal invasion without any complications. Therefore, it can be recommended as the preferred therapy for hepatic metastatic carcinoma after liver transplantation.

A Review on DNA Methylation Occurring in Tissue Culture

Zhen Wang,Xin-Qiang Zheng,Yue-Rong Liang,Kwan-Jeong Song,Jian-Liang Lu 한국차학회 2015 한국차학회지 Vol.- No.S

Tissue culture is an important practice for industrial seedling production and germplasm conservation as well as transgenic operation. More and more evidences proved that DNA methylation change is usually involved in dedifferentiation, continuous cultivation and redifferentiation during tissue culture. DNA methylation variation increases with prolonging culture duration and increasing subculture times which might induce abnormal phenotype of propagules. The pattern and level of DNA methylation are significantly influenced by explants, growth regulators ents. DNA methylation change might reflect the growth and development processes and stress response of cells or tissues during tissue culture. Elucidation of epigenetic variation mechanism might help to improve tissue culture and transgene technology especially for the woody plant with high regeneration difficulty and low transformation frequency.

Characterization of Distribution of Microstructure and Micro-mechanical Properties of Nickel-Based Single Crystal Superalloy Within the Shot-Peened Layer

Ming Liu,Qiang Zheng,Xin Wang,Chunling Xu 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.8

Distributions of hardness, elastic modulus, yield strength, and residual stress within the shot-peened layer of nickel-basedsingle crystal superalloy were measured by instrumented indentation with Berkovich indenter under a constant indentationdisplacement of 400 nm. Elastic modulus is little affected by shot peening, while yield strength calculated by Nobre’s methodis significantly increased. The hardness and residual stress calculated by Vickers hardness testing are also proportional to theresults by instrumented indentation. Indentation parameters such as hardness, indentation work, and contact area linearlydepend on residual stress. Microstructures observed by SEM and EBSD show that the crystal orientation is severely distortedwithin 20 μm from the peened surface. The thickness of the plastic deformation layer measured by EBSD is 60 μm. XRDresults show that the number of diffraction peaks increases after shot peening, indicating the transformation from singlecrystal to polycrystalline structure; residual stress, domain size, microstrain, and dislocation density of shot-peened layerare − 837.5 MPa, 12.88–37.68 nm, 4.39–6.17 × 10–3, and 4.84–8.15 × 1015m−2, respectively. The values of residual stresscalculated by different nanoindentation models are different, but they are proportional to one another with a similar variationwithin the shot-peened surface. David’s model is the most suitable one to assess residual stresses of single crystals byperforming nanoindentation tests on the side surface that is perpendicular to the peened surface. The maximum compressiveresidual stress calculated by David's model is 1.26 GPa at the depth of 38 μm, and the total depth of compressive residualstress is about 130 μm.

A Review on Microbial Decaffeination

Hui-Shi Wu,Xin-Qiang Zheng,Yue-Rong Liang,Jian-Hui Ye,Jian-Liang Lu 한국차학회 2015 한국차학회지 Vol.- No.S

Exclusive exposure of caffeine might bring some adverse effects to human health, and cause some risks to environment. Microbial decaffeination might be a new alternative approach because of its high specificity and efficiency. Many studies revealed that several microorganisms can degrade caffeine, including genera Alcaligenes,Rhodococcus, Klebsiella, Acinetobacter, Enterobacter, Stenotrophomonas and Pseudomonas. Biodegradation of caffeine can be significantly influenced by temperature, pH, aeration rate and initial caffeine concentration of the incubation. There are two main pathways of caffeine biodegradation: C-8 oxidation and N-demethylation, while N-demethylation is the general catabolism pathway in bacteria. Application of microbial decaffeination has also been discussed in this review.

Studies on Chemical Composition of Light Sensitive Albino Tea Cultivars

Kai-Rong Wang,Xin-Qiang Zheng,Ming Li,Long-Jie Zhang,Jing Jin 한국차학회 2015 한국차학회지 Vol.- No.S

Tea quality depends on chemical composition in tea leaves, which varies with genetic factors or tea cultivars, resulting in differences in sensory quality between tea cultivars. To investigate the chemical bases of sensory quality of albino tea cultivars, chemical compositions of light sensitive albino tea cultivars ‘Huangjinya’ and ‘Yujinxiang’ were tested in the present paper. It showed that water soluble extracts were 46.3% and 45.4% on dry base in albino tea cultivars ‘Yujinxiang’ and ‘Huangjinya’. Contents of total amino acids in ‘Yujinxiang’ and ‘Huangjinya’were 5.08% and 5.19%, being 50% higher than ‘Fudingdabai’. However, content of catechins in the albino tea cultivars was significantly lower than ‘Fudingdabai’. It is considered that high levels of water soluble extracts and amino acids, but medium level of polyphenols were the chemical factors leading to the brisk and mellow taste of the albino tea cultivars.

Genotypic analysis of degenerative Cordyceps militaris cultured in the pupa of Bombyx mori

Juan Yin,Xiang-Dong XIN,Yu-JieWENG,Shao-Hui Li,Jun-Qiang JIA,Zhong Zheng Gui 한국곤충학회 2018 Entomological Research Vol.48 No.3

The chemical composition and pharmacological effects of Cordyceps militaris are similar to those of Cordyceps sinensis, with the former undergoing greater development and utilization. Strain degeneration is a common phenomenon that occurs with high frequency during the subculturing of C. militaris, however, and the mechanism underlying strain degeneration remains unclear. In this study, we used touch‐down PCR to compare the ITS1 + 5.8S + ITS2, 18S, 28S and mating‐type (MAT) regions sequence of wild‐type and degenerated strains of C. militaris. We also used quantitative real‐time PCR to analyze expression levels of the CmMAT gene. Sequence analysis showed that the ITS1 + 5.8S + ITS2 and 28S regions of degenerated and wild‐type strains were completely identical, the 18S region of the degenerated strain contained seven single‐base mutations, including six base substitutions and one single‐base insertion. Compared with the wild‐type strain, the degenerated strain contained a deletion of the MAT1–2‐1 region, three base substitutions in the MAT1–1‐1 region, and a base substitution in the MAT1–1‐2 region that causes a glycine‐to‐valine amino acid substitution. Quantitative real‐time PCR analysis detected no CmMAT1–2‐1 gene expression in the degenerated strain, confirming the deletion of the CmMAT1–2‐1 gene. Expression levels of the CmMAT1–1‐1 and CmMAT1–1‐2 genes were significantly down‐regulated to only 7.5 % and 4.4 %, respectively, that of the wild‐type strain. These results indicate that 18S and MAT region mutations, as well as down‐regulated of CmMAT gene expression levels, may play important roles in C. militaris degeneration. This study provides a theoretical basis for further elucidation of the molecular mechanisms of C. militaris degeneration.

Progress in Extraction of Active Components from Tea

Jian-Liang Lu,Xin-Qiang Zheng,Ci-Jie Hu 한국차학회 2015 한국차학회지 Vol.- No.S

Extraction is the first processing step of ready-to-drink (RTD) beverage, instant tea and tea extracts. The extraction efficiency and extracts quality are significantly influenced by material, solvent and condition. The effect of material and solute characteristics, solvent type and property as well as performance conditions was reviewed, and their mechanism was also discussed.

Effects of Green Tea on Blood Pressure and Hypertension-induced Cardiovascular Damage in Spontaneously Hypertensive Rat

Yue-Rong Liang,Shi-Cheng Ma,Xin-Qiang Zheng,Jing-Yi Xu,Ming-Yan Wu,Yi-Wen Luo,Xian-Yang Luo,Jian-Liang Lu 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.1

Three groups of spontaneously hypertensive rats were administered by gavage with distilled water (control group), low-dose green tea (LGT, 0.2 g/kg BW·day) and high-dose green tea (HGT, 1.0 g/kg BW·day) for 4 weeks,during which systolic blood pressure (SBP) was measured weekly by non-invasive tail-cuff method. At the end of experiment, left ventricular hypertrophy index (LHVI) and plasma biochemical indicators were determined, and ultrastructures of myocardium and aortic vascular smooth muscle cells were observed by transmission electron microscopy (TEM). The results show that green tea gavage suppressed the increase in SBP, along with decline in levels of plasma nitric oxide, aldosterone, malondialdehyde, and LHVI, but increased levels of plasma creatinine, calcitonin gene-related peptide, and glutathione peroxidase in a dose dependant manner. Green tea had no effect on plasma total cholesterol. TEM shows that green tea gavage protected mitochondria of left ventricular myocardium and aortic vascular smooth muscle cells from damage.

Advances in Physiological, Biochemical and Molecular Characteristics of the Albino Tea (Camellia sinensis) Plant

Na-na Li,Jian-liang Lu,Xin-qiang Zheng,Yue-rong Liang 한국차학회 2015 한국차학회지 Vol.- No.S

Albino tea cultivars have precious white shoots or yellow shoots and are widely cultivated in China to produce high quality green tea with fresh taste and high aroma, including temperature-sensitive albino mutants and light-sensitive albino mutants. Physiological and biochemical indicators showed that the levels of pigments, total catechins and caffeine decreased, the content of total amino acids, especially theanine increased, and the chloroplast structure were abnormal in albino leaves; molecular studies displayed that expression of genes encoding chloroplast structure and chlorophyll synthesis, such as light harvesting chlorophyll a/b-binding protein, glutamyl-tRNA reductase, Mg-chelatase H subunit, S-adenosylmethionine synthetase and glutamine synthetase, suppressed in albino period