Thermal Deformation Isolation for Satellite Platforms via Flexible Connections

Zheng-Chun Du,Hong-Fu Hou,Zhi-Guo Wang,Jian-Guo Yang 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.12

Thermal deformation is a serious issue for many space structures when travelling around Earth. This paper presents a method to achieve extremely low thermal deformation in satellite platforms with prototype applications. In addition to using the traditional nearzero coefficient of thermal expansion (CTE) material, the platform succeeded in comparison to the traditional energy-consuming methods mainly due to the unique isolation of the residual thermal expansion by flexible connections. First, the design of the composite with near-zero CTE is briefly introduced and used to develop the precision satellite platform. Next, the isolation mechanism to minimize the thermal deformation is presented. Then, the deformation isolation is detailed through the “flexible connecting” method. The effectiveness of this method is demonstrated by finite element (FE) analyses and further verified with a prototype. The experimental results from the prototype recorded a 90% reduction in comparison to the traditional platforms in the wrapping deformation of the payload panel, which was measured by projection moiré methods. The thermal wrapping deformation decreased from 1.013 mm using the rigid connection to 0.104 mm using the flexible connection. This result proves that the proposed method is effective for a high-precision satellite structure and has considerable potential in engineering applications.

Thermal Behavior Analysis and Thermal Error Compensation for Motorized Spindle of Machine Tools

Zheng-Chun Du,Si-Yu Yao,Jian-Guo Yang 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

The thermal error deformation of motorized spindle plays an important role in the precision machining, while error compensation has been proved to be a cost-effective way. Herein a symmetrical solution for the thermal error problem of spindle is proposed based on the thermal behavior analysis. Firstly, the heat generating and transfer mechanism are described considering the heat sources. Next, ANSYS is used to achieve the steady-state and the transient thermal field distribution as well as the related deformation with the given thermal load and boundary condition. Furthermore, the NEM is proposed to predict the thermal error under random rotating speed with no use of thermal sensors, followed by the determination of two important parameters. The verification experiment of the thermal error under random rotating speed is executed. The External Machine Zero Point Shift function of the CNC system is adopted to develop the real-time compensation system on the spindle of HDBS-63 machining center. The maximum axial thermal error is greatly reduced from 55 to 16 um, while the radial one similarly reduced from 15 to 6 um. Both are improved 73% and 63% respectively. The experiment results show that NEM method is simple but of good reliability and practicality.

Shortest Path Analyses in the Protein-Protein Interaction Network of NGAL (Neutrophil Gelatinase-associated Lipocalin) Overexpression in Esophageal Squamous Cell Carcinoma

Du, Ze-Peng,Wu, Bing-Li,Wang, Shao-Hong,Shen, Jin-Hui,Lin, Xuan-Hao,Zheng, Chun-Peng,Wu, Zhi-Yong,Qiu, Xiao-Yang,Zhan, Xiao-Fen,Xu, Li-Yan,Li, En-Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

NGAL (neutrophil gelatinase-associated lipocalin) is a novel cancer-related protein involves multiple functions in many cancers and other diseases. We previously overexpressed NGAL to analyze its role in esophageal squamous cell carcinoma (ESCC). In this study, a protein-protein interaction (PPI) was constructed and the shortest paths from NGAL to transcription factors in the network were analyzed. We found 28 shortest paths from NGAL to RELA, most of them obeying the principle of extracellular to cytoplasm, then nucleus. These shortest paths were also prioritized according to their normalized intensity from the microarray by the order of interaction cascades. A systems approach was developed in this study by linking differentially expressed genes with publicly available PPI data, Gene Ontology and subcellular localizaton for the integrated analyses. These shortest paths from NGAL to DEG transcription factors or other transcription factors in the PPI network provide important clues for future experimental identification of new pathways.

Prognostic Impact of Elevation of Vascular Endothelial Growth Factor Family Expression in Patients with Non-small Cell lung Cancer: an Updated Meta-analysis

Zheng, Chun-Long,Qiu, Chen,Shen, Mei-Xiao,Qu, Xiao,Zhang, Tie-Hong,Zhang, Ji-Hong,Du, Jia-Jun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: The vascular endothelial growth factor family has been implicated in tumorigenesis and metastasis. The prognostic value of each vascular endothelial growth factor family member, particular VEGF/VEGFR co-expression, in patients with non-small lung cancer remains controversial. Materials and Methods: Relevant literature was identified by searching PubMed, EMBASE and Web of Science. Studies evaluating expression of VEGFs and/or VEGFRs by immunohistochemistry or ELISA in lung cancer tissue were eligible for inclusion. Hazard ratios (HRs) and 95% confidence intervals (CIs) from individual study were pooled by using a fixed- or random-effect model, heterogeneity and publication bias analyses were also performed. Results: 74 studies covering 7,631 patients were included in the meta-analysis. Regarding pro-angiogenesis factors, the expression of VEGFA (HR=1.633, 95%CI: 1.490-1.791) and VEGFR1 (HR=1.924, 95%CI: 1.220-3.034) was associated separately with poor survival. Especially, VEGFA over-expression was an independent prognostic factor in adenocarcinoma (ADC) (HR=1.775, 95%CI: 1.384-2.275) and SCC (HR=2.919, 95%CI: 2.060-4.137). Co-expression of VEGFA/VEGFR2 (HR=2.011, 95%CI: 1.405-2.876) was also significantly associated with worse survival. For lymphangiogenesis factors, the expression of VEGFC (HR=1.611, 95%CI: 1.407-1.844) predicted a poor prognosis. Co-expression of VEGFC/VEGFR3 (HR=2.436, 95%CI: 1.468-4.043) emerged as a preferable prognostic marker. Conclusions: The expression of VEGFA (particularly in SCC and early stage NSCLC), VEGFC, VEGFR1 indicates separately an unfavorable prognosis in patients with NSCLC. Co-expression VEGFA/VEGFR2 is comparable with VEGFC/VEGFR3, both featuring sufficient discrimination value as preferable as prognostic biologic markers.

Physiological character and molecular mapping of leaf-color mutant wyv1 in rice (Oryza sativa L.)

Xian-chun Sang,Li-kui Fang,Yuenyong Vanichpakorn,Ying-hua Ling,Peng Du,Fang-ming Zhao,Zheng-lin Yang,Guang-hua He 한국유전학회 2010 Genes & Genomics Vol.32 No.2

The seed of an excellent indica restorer line Jinhui10 (Oryza sativa L. ssp. indica) was treated by ethyl methanesulfonate (EMS); a leaf-color mutant displaying distinct phenotype throughout development grown in paddy field was identified from the progeny. The mutant leaf showed white-yellow at seedling stage and then turned to yellow-green at tillering stage, after that, virescent color appeared until to maturity. The mutant was thus temporarily designed as wyv1. The chlorophyll contents decreased significantly and the changing was consistent with the chlorotic level of wyv1 leaves. Chlorophyll fluorescence kinetic parameters measured at the seedling stage showed that co-efficiency of photochemical quenching (qP),actual photosystem II efficiency (ΦPS II), electron transport rate (ETR) and initial chlorophyll fluorescence level (Fo), net photosynthetic rate (Pn) and maximum photochemical efficiency (Fv / Fm) significantly decreased in severe chlorotic leaf of the mutant compared with that of wild type. However,no significant differences were observed for Pn and Fv/Fm between virescent leaf and normal green leaf. Genetic analysis suggested that the mutant phenotype was controlled by a single recessive nuclear gene which was finally mapped between SSR marker Y7 and Y6 on rice chromosome 3 based on F2 population of Xinong1A / wyv1. Genetic distances were 0.06 cM and 0.03 cM respectively, and the physical distance was 84kb according to the sequence of indica rice 9311. The results must facilitate map-based cloning and functional analysis of WYV1 gene.

Gene Mapping Related to Yellow Green Leaf in a Mutant Line in Rice (Oryza sativa L.)

Peng Du,Ying Hua Ling,Xian Chun Sang,Fang Ming Zhao,Rong Xie,Zheng Lin Yang,Guang Hua He 한국유전학회 2009 Genes & Genomics Vol.31 No.2

A mutant, which derived from the restorer line Jinhui10 treated with EMS, showed completely yellow green leaves, and it had low chlorophyll content and poor agronomic characteristics during the growing stage. The F1 plants from the cross between normal × the mutant showed normal green leaves, and the segregation ratio of normal to yellow green leaves was 3:1 in F2 population. It indicated that the trait was controlled by a single recessive nuclear gene, temporarily designated as ygl3. The gene ygl3 was mapped between RM468 and RM3684 with genetic distances 8.4 cM and 1.8 cM on chromosome 3. This result would be used as genetic information for fine mapping and map-based cloning of ygl3 gene.

Dynamic temperature gradient and unfalsified control approach for machine tool thermal error compensation

Xiao-dong Yao,Zheng-Chun Du,Guang-yan Ge,Jian-Guo Yang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

In this work, a novel machine tool thermal error modeling method based on dynamic temperature gradient is proposed, and a thermal error compensation method based on unfalsified control is developed. The dynamic temperature gradient is used to optimize the locations of temperature measuring points on the machine tool. Real-time compensation for the thermal error can be achieved using the developed compensation method by establishing the correlations between dynamic temperature gradient and thermal error in the machine tool. Different from traditional model-based methods, the developed compensation approach does not rely on an accurate model of the thermal error but instead uses online input/output data to adaptively select the best controller at any moment, thereby improving thermal error prediction accuracy and robustness. The effectiveness of the developed thermal error compensation method is demonstrated on a turning center, where the spindle thermal error is compensated during the manufacturing of 120 inner bore parts and 120 shaft parts. After compensation using the proposed approach, thermal errors are reduced from 27 µm to 9 µm for the inner bore parts and from 31 µm to 11 µm for the shaft parts, respectively.

The Compact Pulsed Hadron Source: A Design Perspective

Jie Wei,Huaibi Chen,Cheng Cheng,Qiang Du,Zhe Feng,Xialin Guan,Xiaoxue Han,Tuchen Huang,Renkai Li,Chun K. Loong,Beibei Shao,Chuanxiang Tang,Qingzi Xing,Yigang Yang,Hao Zha,Huayi Zhang,Shuxin Zheng,Bin 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.61

During the past decades, large-scale national neutron sources have been developed in Asia, Europe,and North America. Complementing such efforts, compact hadron beam complexes and neutron sources intended to serve primarily universities and industrial institutes have been proposed,and some have recently been established. Responding to the demand in China for pulsed neutron/proton-beam platforms that are dedicated to fundamental and applied research for users in multiple disciplines from materials characterization to hadron therapy and radiography to accelerator-driven sub-critical reactor systems (ADS) for nuclear waste transmutation, we have initiated the construction of a compact, yet expandable, accelerator complex-the Compact Pulsed Hadron Source (CPHS). It consists of an accelerator front-end (a high-intensity ion source, a 3-MeV radio-frequency quadrupole linac (RFQ), and a 13-MeV drift-tube linac (DTL)), a neutron target station (a beryllium target with solid methane and room-temperature water moderators/reflector),and experimental stations for neutron imaging/radiography, small-angle scattering, and proton irradiation. In the future, the CPHS may also serve as an injector to a ring for proton therapy and radiography or as the front end to an ADS test facility. In this paper, we describe the design of the CPHS technical systems and its intended operation.