Fast Response Research of Magnetically Controlled Reactor

Chen Feng,Wang Jun,Zheng Hao,Lu Wenhua,Tian Cuihua,Yuan Jian,Chen Baichao,Yuan jiaxin 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.10

As a kind of reactive power compensation equipment with control flexibility and high reliability, magnetically controlled reactor (MCR) is widely used in reactive power compensation, over-voltage limitation and other aspects. However, low responding speed has severely limited the application of MCR. Especially when applied to suppress voltage flicker and arc suppression coil, the slow response of MCR will decrease the stability of control system, even causing the system shock. To improve the response performance of MCR, in this paper, the working principle of MCR has been analyzed, and a fast response structure of MCR has been designed with the novel fast response structure, fast excitation and rapid demagnetization can be achieved. According to the simulation and experiment results, the effectiveness of the proposed structure is verified by limiting the response time in 30ms.

Experimental study on cold-formed lipped channel stub columns reinforced by steel bars or steel strips

Jian-Feng Chen,Ming-Qi Chen,Yong-Kang Shen,Jian-Hua Shao,Xin-Xin Yang 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.3

In this paper, the axial compressive properties of cold-formed steel lipped channel stub columns strengthened by rebars or steel strips are experimentally studied. The experiment included two sections. A kind of columns with local buckling is reinforced longitudinally by steel strips at the web. The other is the columns with distorted buckling, which is reinforced longitudinally by steel bars at the curling edge. The failure mode, deformation characteristics, ultimate bearing capacity and load displacement curve of the specimen are obtained through the experiment. On the basis of the experiment, the calculation results of theoretical axial bearing capacity of cold-formed steel lipped channel stub columns in Chinese, North American and Australian code are compared and analyzed. Research indicates: First, the cold-formed steel lipped channel stub columns strengthened by steel bars or steel strips can effectively improve the compressive bearing capacity of the specimen. Secondly, when the initial stress ratio of specimen is less than 0.3, the reinforcement effect is ideal. Thirdly, the three standards don’t stipulate the calculation of theoretical bearing capacity of the specimen strengthened after loading, so there is a large deviation between the theoretical calculation value and the test value.

Analysis of Small Fragment Deletions of the APC gene in Chinese Patients with Familial Adenomatous Polyposis, a Precancerous Condition

Chen, Qing-Wei,Zhang, Xiao-Mei,Zhou, Jian-Nong,Zhou, Xin,Ma, Guo-Jian,Zhu, Ming,Zhang, Yuan-Ying,Yu, Jun,Feng, Ji-Feng,Chen, Sen-Qing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

Background: : Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease mainly caused by mutations of the adenomatous polyposis coli (APC) gene with almost complete penetrance. These colorectal polyps are precancerous lesions that will inevitable develop into colorectal cancer at the median age of 40-year old if total proctocolectomy is not performed. So identification of APC germline mutations has great implications for genetic counseling and management of FAP patients. In this study, we screened APC germline mutations in Chinese FAP patients, in order to find novel mutations and the APC gene germline mutation characteristics of Chinese FAP patients. Materials and Methods: The FAP patients were diagnosed by clinical manifestations, family histories, endoscope and biopsy. Then patients peripheral blood samples were collected, afterwards, genomic DNA was extracted. The mutation analysis of the APC gene was conducted by direct polymerase chain reaction (PCR) sequencing for micromutations and multiplex ligation-dependent probe amplification (MLPA) for large duplications and/or deletions. Results: We found 6 micromutations out of 14 FAP pedigrees, while there were no large duplications and/or deletions found. These germline mutations are c.5432C>T(p. Ser1811Leu), two c.3926_3930delAAAAG (p.Glu1309AspfsX4), c.3921_3924delAAAA (p.Ile1307MetfsX13), c3184_3187delCAAA(p.Gln1061AspfsX59) and c4127_4126delAT (p.Tyr1376LysfsX9), respectively, and all deletion mutations resulted in a premature stop codon. At the same time, we found c.3921_3924delAAAA and two c.3926_3930delAAAAG are located in AAAAG short tandem repeats, c3184_3187delCAAA is located in the CAAA interrupted direct repeats, and c4127_4128 del AT is located in the 5'-CCTGAACA-3', 3'-ACAAGTCC-5 palindromes (inverted repeats) of the APC gene. Furthermore, deletion mutations are mostly located at condon 1309. Conclusions: Though there were no novel mutations found as the pathogenic gene of FAP in this study, we found nucleotide sequence containing short tandem repeats and palindromes (inverted repeats), especially the 5 bp base deletion at codon 1309, are mutations in high incidence area in APC gene,.

A Novel EYA1 Mutation Causing Alternative RNA Splicing in a Chinese Family With Branchio-Oto Syndrome: Implications for Molecular Diagnosis and Clinical Application

Anhai Chen,Chufeng He,Yong Feng,Jie Ling,Xin Peng,Xianlin Liu,Shuang Mao,Yongjia Chen,Mengyao Qin,Shuai Zhang,Yijiang Bai,Jian Song,Zhili Feng,Lu Ma,Dinghua He,Lingyun Mei1 대한이비인후과학회 2023 Clinical and Experimental Otorhinolaryngology Vol.16 No.4

Objectives. Branchio-oto syndrome (BOS) primarily manifests as hearing loss, preauricular pits, and branchial defects. EYA1is the most common pathogenic gene, and splicing mutations account for a substantial proportion of cases. However,few studies have addressed the structural changes in the protein caused by splicing mutations and potential pathogenicfactors, and several studies have shown that middle-ear surgery has limited effectiveness in improving hearing in thesepatients. BOS has also been relatively infrequently reported in the Chinese population. This study explored the ge-netic etiology in the family of a proband with BOS and provided clinical treatment to improve the patient’s hearing. Methods. We collected detailed clinical features and peripheral blood samples from the patients and unaffected individualswithin the family. Pathogenic mutations were identified by whole-exome sequencing and cosegregation analysis andclassified according to the American College of Medical Genetics and Genomics guidelines. Alternative splicing wasverified through a minigene assay. The predicted three-dimensional protein structure and biochemical experimentswere used to investigate the pathogenicity of the mutation. The proband underwent middle-ear surgery and was fol-lowed up at 1 month and 6 months postoperatively to monitor auditory improvement. Results. A novel heterozygous EYA1 splicing variant (c.1050+4 A >C) was identified and classified as pathogenic (PVS1(RNA),PM2, PP1). Skipping of exon 11 of the EYA1 pre-mRNA was confirmed using a minigene assay. This mutation mayimpair EYA1-SIX1 interactions, as shown by an immunoprecipitation assay. The EYA1-Mut protein exhibited cellularmislocalization and decreased protein expression in cytological experiments. Middle-ear surgery significantly improvedhearing loss caused by bone-conduction abnormalities in the proband. Conclusion. We reported a novel splicing variant of EYA1 in a Chinese family with BOS and revealed the potential molec-ular pathogenic mechanism. The significant hearing improvement observed in the proband after middle-ear surgeryprovides a reference for auditory rehabilitation in similar patients.

Remarkably efficient hydrolysis of cinnamaldehyde to natural benzaldehyde in amino acid ionic liquids

Duan-Jian Tao,Xiang-Shu Chen,Shu Xu,Feng-Feng Chen,Yan Zhou,Xin Zhao,Li-Li Yu,Kuan Huang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.12

The hydrolysis of cinnamaldehyde to natural benzaldehyde was investigated systematically using tetramethylammonium- based amino acid ionic liquids as homogeneous catalysts. The results indicated that tetramethylammonium prolinate ([N1111][Pro]) can be a powerful catalyst for the highly efficient hydrolysis of cinnamaldehyde, in which natural benzaldehyde was obtained with almost 94% yield and over 99% selectivity in 1 h. Moreover, kinetic study showed that compared with other catalysts, the catalytic system of [N1111][Pro] has a lower activation energy of 38.30 kJ·mol−1 in the hydrolysis reaction, indicating superior catalytic performance of [N1111][Pro]. Quantum-mechanical calculations further manifested that such high performance originates from the cooperative catalysis of the secondary amino and carboxyl group in the anion [Pro].

Tuning the acidity of sulfonic functionalized ionic liquids for highly efficient and selective synthesis of terpene esters

Duan-Jian Tao,Yan Dong,Zhi-Jun Cao,Feng-Feng Chen,Xiang-Shu Chen,Kuan Huang 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.41 No.-

A series of sulfonic functionalized ionic liquids (SFILs) with different acidity were designed and preparedfor the synthesis of terpene esters (e.g. geranyl acetate). The effect of acidity of SFILs on their performancewas investigated systematically. It is found that tuning the acidity of SFILs to an appropriate value resultsin not only high conversion of geraniol but also superior selectivity of geranyl acetate. The SFILs can beeasily separated from products byfiltration under room temperature, thus showing good reusability. Furthermore, the kinetics for SFILs in the esterification of geraniol were determined as the basis for futureprocess design.

Austenite Grain Growth Behavior of 30BF Steel Before Rough Rolling

Yong‑feng Chen,Jian‑bo Xie,Yan‑xin Wu,Jian‑xun Fu 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

To investigate the eff ect of heat treatment on the grain size of austenite in 30BF steel, the comparisons of the morphologiesand sizes of austenite grains between heating samples were made with a high-temperature electric resistance furnace, andthe austenite growth models were built with method of mathematics. The results show that most grains in original specimenwith the sizes below 70 μm uniformly distributed. At a heating rate ( v ) of 10 °C/s, the grain size ( d ) value under a certain time( t ) increased by 60–100 μm with raising temperature ( T ) from 850 to 1100 °C, whereas the d value under a certain T merelyincreased by 70–120 μm with raising time to 60 min. Under v = 0.1 °C/s, T = 850 °C, and t = 0 s, the occupied ratio of grainswith sizes of 40–50 μm was 0.165, whereas at 900 °C, the occupied ratio was 0.125. The evolutions of ln (d5.8− d5.80 ) with1/ T were in negative linear correlations, whereas the ln (d5.8− d5.80 ) with ln t were in positive linear correlations. To sum up,the grain growth behavior of steel was elucidated.

Preparation, self-assembly and performance modulation of gold nanoparticles decorated ferrocene-containing hybrid block copolymer multifunctional materials

Jian-Guo Zhang,Xue-Yin Zhang,Hua Yu,Yan-Ling Luo,Feng Xu,Ya-Shao Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.65 No.-

Gold nanoparticles decorated stimuli-responsive copolymer hybrids, poly(2-methacryloyloxyethyl ferrocenecarboxylate)-block-poly(N-isopropylacryamide) decorated with gold nanoparticles, were synthesized through two-step successive RAFT and ensuing in-situ reduction. The hybrids could self-assemble into interesting micelle structures from globular, wormlike to rodlike shapes by altering the quality and compositions of solvents and ionic strength, and exhibited multifunctionality including quasi-reversible electrochemical behavior, redox-stress responsiveness and temperature sensitivity. The physicochemical and electrochemical properties were modulated by tailor-making the system compositions and redox reaction. The copolymer hybrids were expected to broaden their applications in nanobiomedicine including targeted drug carriers and magnetic resonance imaging, optical, electrochemical catalyst, optoelectronics and sensors etc.

Four logarithmically completely monotonic functions involving gamma function

Feng Qi,Da-Wei Niu,Jian Cao,Shou-Xin Chen 대한수학회 2008 대한수학회지 Vol.45 No.2

In this paper, two classes of functions, involving a parameter and the classical Euler gamma function, and two functions, involving the classical Euler gamma function, are verified to be logarithmically completely monotonic in (-½, ∞) or (0, ∞); some inequalities involving the classical Euler gamma function are deduced and compared with those originating from certain problems of traffic flow, due to J. Wendel and A. Laforgia, and relating to the well known Stirling’s formula. In this paper, two classes of functions, involving a parameter and the classical Euler gamma function, and two functions, involving the classical Euler gamma function, are verified to be logarithmically completely monotonic in (-½, ∞) or (0, ∞); some inequalities involving the classical Euler gamma function are deduced and compared with those originating from certain problems of traffic flow, due to J. Wendel and A. Laforgia, and relating to the well known Stirling’s formula.

Inhibitory Effects of α-Pinene on Hepatoma Carcinoma Cell Proliferation

Chen, Wei-Qiang,Xu, Bin,Mao, Jian-Wen,Wei, Feng-Xiang,Li, Ming,Liu, Tao,Jin, Xiao-Bao,Zhang, Li-Rong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Background: Pine needle oil from crude extract of pine needles has anti-tumor effects, but the effective component is not known. Methods: In the present study, compounds from a steam distillation extract of pine needles were isolated and characterized. Alpha-pinene was identified as an active anti-proliferative compound on hepatoma carcinoma BEL-7402 cells using the MTT assay. Results: Further experiments showed that ${\alpha}$-pinene inhibited BEL-7402 cells by arresting cell growth in the G2/M phase of the cell cycle, downregulating Cdc25C mRNA and protein expression, and reducing cycle dependence on kinase 1(CDK1) activity. Conclusion: Taken together, these findings indicate that ${\alpha}$-pinene may be useful as a potential anti-tumor drug.