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Hot Forging Process Design Optimization Based on Approximate Model and FEM Simulation
Chen, Xue Wen,Jung, Dong Won,Sun, Ai Xue Trans Tech Publications, Ltd. 2008 Materials science forum Vol.575 No.-
<P>Technology and die design are very important in the development of forging products due to its great influence on the quality, cost and manufacturing efficiency of the final products as well as the life of the forging die. In the environment of the severe competition, how to improve the quality of forging technology and die design, to reduce the product cost and ultimately to enhance competitiveness of the forging factory are the problems that forging technology and die designer have to solve. In order to improve the quality of forging technology and die design, a design optimization method based on approximate model (response surface model) and FEM technique for hot forging process is proposed in this paper. During design optimization process, finite element analysis is incorporated to calculate the objective function and check the design alternatives. Design of experiment (DOE) method is used to collect sample points and calculate the polynomial coefficients of response surface model, and approximate model is used to calculate the optimum search direction. Finally, a case study is conducted for a gear workpiece hot forging process. The objective function is the degree of uniformity of equivalent-strain, which can be defined as mean square deviation of the equivalent-strain in each element and the average equivalent-strain of all elements, and the design parameters are the initial H0/D0 ratio of billet and the key dimensions of the die. Then the design optimization mathematical model is established. The result shows that the objective function value is dropped from 0.7914 and converges at 0.4843 within 17 iterations, the optimal design parameters are obtained.</P>
Efficient production of glutathione using hydrolyzate of banana peel as novel substrate
Xue-Dong Chen,Gong-Yuan Wei,Jun-Li Zhang,Ying-Ying Dong 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.7
The hydrolyzate of banana peels containing abundant fermentable sugars as glucose, xylose, mannose,and arabinose was successfully used as a novel substrate for the efficient production of glutathione by Candida utilis SZU 07-01. Xylose was first selected as the sole carbon source for glutathione production, medium optimization for better cell growth and higher glutathione using response surface methodology consisting of PB design, the steepest ascent experiment and CCD was carried out, and the optimal combination of nutrients was obtained as follows: xylose 20 g/L, (NH_4)-2SO_4 9.59 g/L, KH_2PO_4 3 g/L, L-methionine 5.72 g/L and MgSO_4 0.20 g/L. The maximum dry cell weight and glutathione achieved using the optimized medium were 7.36 g/L and 154.32 mg/L, respectively. Following with the content in this medium, other sugars like glucose, mannose and arabinose were chosen as the sole carbon source and all tested available for glutathione production. Based on these results, the hydrolyzate of banana peels was selected as a novel substrate, and a high DCW of 7.68 g/L and glutathione yield of 111.33 mg/L were obtained with the initial sugar concentration of 20 g/L in the hydrolyzate of banana peels.
Two new ursane-type triterpenoid saponins from Elsholtzia bodinieri
Jin-Dong Zhong,Xue-Wei Zhao,Xuan-Qin Chen,Hong-Mei Li,Chin-Ho Chen,Xue-Shan Xia,Rong-Tao Li 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.6
Two new ursane-type triterpenoid saponins,bodiniosides M (1) and N (2), along with three knownsaponins, oblonganosides I (3), pseudobuxussaponin B (4)and bodinioside A (5), were isolated from the aerial partsof Elsholtzia bodinieri. The structures of compounds 1 and2 were characterized by spectroscopic data as well as acidhydrolysis and GC analysis as 3-O-b-D-xylopyranosyl-19ahydroxy-23-acetoxy-urs-12(13)-en-28-oic acid 28-O-a-Lrhamnopyranosyl-(1-2)-b-D-glucopyranoside and 3-O-b-Dglucopyranosyl-2a,19a-dihydroxy-urs-12(13)-en-28,20blactone. Compounds 1 and 5 exhibited potent anti-HCVactivities in vitro with a selective index of 6.53 and 4.41,respectively.
Analysis the role of arabidopsis CKRC6/ASA1 in auxin and cytokinin biosynthesis
Dong-Wei Di,Lei Wu,Pan Luo,Li Zhang,Tian-Zi Zhang,Xue Sun,Shao-Dong Wei,Chen-Wei An,Guang-Qin Guo 한국식물학회 2016 Journal of Plant Biology Vol.59 No.2
The crosstalk between auxin and cytokinin (CK) is important for plant growth and development, although the underlying molecular mechanisms remain unclear. Here, we describe the isolation and characterization of a mutant of Arabidopsis Cytokinin-induced Root Curling 6 (CKRC6), an allele of ANTHRANILATE SYNTHASE ALPHA SUBUNIT 1 (ASA1) that encodes the á-subunit of AS in tryptophan (Trp) biosynthesis. The ckrc6 mutant exhibits root gravitropic defects and insensitivity to both CK and the ethylene precursor 1-aminocyclopropane-1-carboxylicacid (ACC) in primary root growth. These defects can be rescued by exogenous indole-3-acetic acid (IAA) or tryptophan (Trp) supplementation. Furthermore, our results suggest that the ckrc6 mutant has decreased IAA content, differential expression patterns of auxin biosynthesis genes and CK biosynthesis isopentenyl transferase (IPT) genes in comparison to wild type. Collectively, our study shows that auxin controls CK biosynthesis based on that CK sensitivity is altered in most auxin-resistant mutants and that CKs promote auxin biosynthesis but inhibit auxin transport and response. Our results also suggest that CKRC6/ASA1 may be located at an intersection of auxin, CK and ethylene metabolism and/or signaling.
A New Chromone Glycoside from Rhododendron spinuliferum
Chen, Gang,Jin, Hui Zi,Li, Xue Feng,Zhang, Qi,Shen, Yun Heng,Yan, Shi Kai,Zhang, Wei Dong 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.8
A new chromone glycoside, 3,5,7-trihydroxylchromone-3-O-$\alpha$-L-arabinopyranoside (1), together with quercetin (2), (+)-catechin (3), (-)-epi-catechin (4) were isolated from the aerial parts of Rhododendron spinuliferum. The structure of 1 was elucidated on the basis of spectroscopic and 2D-NMR spectral analysis. In addition, 1 exhibited mild inhibitory effect on NO production in LPS-stimulated RAW264.7 cells.
Xue-Chang Wu,Wei-Feng Chen,Chao-Dong Qian,Ou Li,Ping Li,Yan-Ping Wen 한국미생물학회 2007 The journal of microbiology Vol.45 No.6
A new antagonistic strain of actinomycete, designated AP19-2, was isolated from the feces of giant pandas inhabiting the Foping National Nature Reserve in China. Cultural characteristic studies strongly suggested that this strain is a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene of strain AP19-2 evidenced profound similarity (97-99%) with other Streptomyces strains. Two pure active molecules were isolated from a fermentation broth of Streptomyces sp. strain AP19-2 via extraction, concentration, silica gel G column chromatography, and HPLC. The chemical structures of the two related compounds (referred to as chromomycin A2 and chromomycin A3) were established on the basis of their Infrared spectra (IR), High Resolution Electrospray Ionization Mass Spectrometry (HR-ESI-MS), and Nuclear Magnetic Resonance (NMR) data, and by comparison with published data.
Chen, Nian-Ke,Li, Xian-Bin,Bang, Junhyeok,Wang, Xue-Peng,Han, Dong,West, Damien,Zhang, Shangbai,Sun, Hong-Bo American Physical Society 2018 Physical review letters Vol.120 No.18
<P>Time-dependent density-functional theory molecular dynamics reveals an unexpected effect of optical excitation in the experimentally observed rhombohedral-to-cubic transition of GeTe. The excitation induces coherent forces along [001], which may be attributed to the unique energy landscape of Peierls-distorted solids. The forces drive the A(lg) optical phonon mode in which Ge and Te move out of phase. Upon damping of the A(1)g mode, phase transition takes place, which involves no atomic diffusion, defect formation, or the nucleation and growth of the cubic phase.</P>
( Xue Liang Niu ),( Xiao Ran Hao ),( Zhang Yong Hong ),( Long Fei Chen ),( Xi Yu ),( Xu Dong Zhu ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.5
Fungi of the genus Pestalotiopsis have drawn attention for their capability to produce an array of bioactive secondary metabolites that have potential for drug development. Here, we report the determination of a polyketide derivative compound, pestalotiollide B, in the culture of the saprophytic fungus Pestalotiopsis microspora NK17. Structural information acquired by analyses with a set of spectroscopic and chromatographic techniques suggests that pestalotiollide B has the same skeleton as the penicillide derivatives, dibenzodioxocinones, which are inhibitors of cholesterol ester transfer protein (CETP), and as purpactins A and C’, inhibitors of acyl-CoA:cholesterol acyltransferase (ACAT). Strain NK17 can make a fairly high yield of pestalotiollide B (i.e., up to 7.22 mg/l) in a constitutive manner in liquid culture. Moreover, we found that a putative histone deacetylase gene, designated as hid1, played a role in the biosynthesis of pestalotiollide B. In the hid1 null mutant, the yield of pestalotiollide B increased approximately 2-fold to 15.90 mg/l. In contrast, deletion of gene hid1 led to a dramatic decrease of conidia production of the fungus. These results suggest that hid1 is a modulator, concerting secondary metabolism and development such as conidiation in P. microspora. Our work may help with the investigation into the biosynthesis of pestalotiollide B and the development for new CETP and ACAT inhibitors.