Characterization of the effect of He⁺ irradiation on nanoporous-isotropic graphite for molten salt reactors

Zhang, Heyao,He, Zhao,Song, Jinliang,Liu, Zhanjun,Tang, Zhongfeng,Liu, Min,Wang, Yong,Liu, Xiangdong Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.6

Irradiation-induced damage of binderless nanoporous-isotropic graphite (NPIG) prepared by isostatic pressing of mesophase carbon microspheres for molten salt reactor was investigated by 3.0 MeV He⁺ irradiation at room temperature and high temperature of 600 ℃, and IG-110 was used as the comparation. SEM, TEM, X-ray diffraction and Raman spectrum are used to characterize the irradiation effect and the influence of temperature on graphite radiation damage. After irradiation at room temperature, the surface morphology is rougher, the increase of defect clusters makes atom flour bend, the layer spacing increases, and the catalytic graphitization phenomenon of NPIG is observed. However, the density of defects in high temperature environment decreases and other changes are not obvious. Mechanical properties also change due to changes in defects. In addition, SEM and Raman spectra of the cross section show that cracks appear in the depth range of the maximum irradiation dose, and the defect density increases with the increase of irradiation dose.

Investigation of Quench Sensitivity and Microstructure Evolution During Isothermal Treatment in 2195 Al–Li Alloy

Zhiwu Zhang,Youping Yi,Wen You,Shiquan Huang,Yonglin Guo,Hailin He 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

To investigate the quenching sensitivity of the 2195 Al–Li alloy rolled sheet and guide the design of the quenching process,the time–temperature-property (TTP) curves of this material were researched through interrupted quenching experiments. The differential scanning calorimetry (DSC) and transmission electron microscope (TEM) were used to characterize theevolution of precipitates during isothermal treatment. The results of this essay demonstrated that the nose temperature of 2195Al–Li alloy is around 370 °C and the temperature range of quenching sensitivity is 340 °C to 400 °C. The microstructureobservation revealed that the T1particles precipitate and grow rapidly at the temperature from 340 to 400 °C, which is dueto the high nucleation rate of phase and fast solute diffusion kinetics, especially at the nose temperature. The needle-shapedθ′/θ″ and T1particles grow up quickly as the isothermal preservation time prolonged, leading to the decrease of the supersaturatedsolid solution of the matrix. This will reduce the number of the age-induced precipitate and weaken the subsequentage hardening effect. Therefore, the rate of cooling should be increased in the quenching sensitivity range (340–400 °C) toinhibit the precipitation of the second phase and obtain excellent mechanical properties. While in other temperature ranges,the cooling rate should be decreased appropriately to reduce residual stress. The appropriate average cooling rate is recommendedto be around 13 °C s−1 at the temperature from 340 to 400 °C.

Unveiling of the energy storage mechanisms of multi -modified (Nb2O5@C)/rGO nanoarrays as anode for high voltage supercapacitors with formulated ionic liquid electrolytes

Zhang, Jiahe,Zhang, Haitao,Zhang, Yaqin,Zhang, Junwei,He, Hongyan,Zhang, Xixiang,Shim, Jae-Jin,Zhang, Suojiang Elsevier 2019 ELECTROCHIMICA ACTA Vol.313 No.-

Tracking the movement trajectory of newly emerged adult Chinese citrus flies with insect harmonic radar

Zhang-Zhang He,Jie Luo,Lian-You Gui,Deng-Ke Hua,Tian-Hua Du,Fu-Lian Wang,Peng Liang,Yong-Fang Shi,Xuan Yang 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Previous work reveals that the adult Chinese citrus fly, Bactrocera minax (Enderlein), emerges from the ground in citrus orchards and presumably disperses to alternate food sources in neighboring shrubs and trees, where it stays and becomes reproductively mature, and then later returns to the orchard to lay eggs. We investigated the trajectories of early emerged adult Chinese citrus flies, which were tracked with portable harmonic radar in 2013, 2014, 2015, and 2016 in four different habitats in Hubei province of China that presumably provided food sources for adults. This study we investigated whether early emerged adult Chinese citrus flies migrate into forests. A total of 47 adults were tracked following release in a citrus orchard. Our results showed that a total of 33 adults released in a citrus orchard flew into the forest, and 14 adults that disappeared during the tracking process in the citrus orchard. A total of 10 adults (in 2014) that were tracked and released in the forest flew to the forest. Of the adult flies investigated, 54.5% flew directly into the forest, while the remaining 45.5% finally arrived in the forest after repeatedly adjusting their trajectories. When there were Castanea mollissima Blume (Fagaceae) in the surrounding forest, the proportion of frequency of adult landing on the plant represented 58.3% and 88.5% of landing on all species in 2014 and in 2015, respectively. We conclude that early emerged adult Chinese citrus flies in the mosaic-type citrus orchard of the hilly terrain landform dispersed into adjacent forest.

Spatial Analysis of Rural Medical Facilities Using Huff Model : A Case Study of Lankao County, Henan Province

Pengyan Zhang,,Xing Ren,Qianqian Zhang,Jianjian He,Yongmin Chen 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.1

Rural health care reformed in the new situation in China, indicating that the construction of medical facilities not only to solve difficult medical problems, but also to take into account the efficiency and fairness of the use of medical resources allocation. Facing these problems, the paper aims to assess the spatial distribution of rural medical services by using geographic information systems (GIS) and spatial accessibility indexes. Lankao County in Henan Province and 21 hospitals of township and county are selected as study samples. First adopted ArcGIS10.0 to collate data. Second, the authors established a network dataset to analysis the maximum coverage for hospital services space accessibility. At last, established Huff model and built a scientific evaluation for the current hospitals’ distribution. There are several findings from the case study. First, the distribution of medical facility is unbalanced in rural areas in term of per capita, such as opportunity for assessing medical services and the convenience of utilizing medical services. Second, by using the Huff Model to calculate the potential population in service regions, the Huff Model to calculate the potential population in service regions, the results showed the low efficiency of the use of medical resources and the problems in these regions.

Analog Fault Detection Comparison between Supply Current and Output Voltage

Chaojie Zhang,Guo He,Qiaobin Zhang 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11

In view of the difficulties caused by determining threshold for fault detection of analog circuits, a method based on principal component analysis (PCA) was proposed to overcome these difficulties. The basic model of the proposed method and the general rule for analog fault detection were described in detail. Power supply current test has the advantages that only one test point is needed and there is no need to propagate fault effects to the outputs. Fault detection of analog circuits using PCA of power supply current was evaluated by experiment. The signal filtering and amplifying circuit used in the ultrasonic liquid sensor was selected as the research object. And the detection results using power supply current are compared with those using the output voltage under the same stimulus. The results show that the PCA based method can use the information in both time and frequency domain simultaneously, and it can overcome the difficulty in determining threshold by the expert’s empirical knowledge. These make it a more suitable candidate for fault detection of analog circuits than pure time-domain or pure frequency-domain methods.

Roles of Immunohistochemical Staining in Diagnosing Pulmonary Squamous Cell Carcinoma

Yan, Yue,Zhang, Ya-Xiong,Fang, Wen-Feng,Kang, Shi-Yang,Zhan, Jian-Hua,Chen, Nan,Hong, Shao-Dong,Liang, Wen-Hua,Tang, Yan-Na,He, Da-Cheng,Wu, Xuan,Zhang, Li Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: Differentiating morphologic features based on hematoxylin-eosin (HE) staining is the most common method to classify pathological subtypes of non-small-cell lung cancer (NSCLC). However, its accuracy and inter-observer reproducibility in pathological diagnosis of poorly differentiated NSCLC remained to be improved. Materials and Methods: We attempted to explore the role of immunohistochemistry (IHC) staining in diagnosing pulmonary squamous cell carcinoma (SQCC) with poorly differentiated features by HE staining or with elevated serum adenocarcinoma-specific tumor markers (AD-TMs). We also compared the difference of epidermal growth factor receptor (EGFR) mutation rate between patients with confirmed SQCC and those with revised pathological subtype. Logistic regression analyses were used to test the association between different factors and diagnostic accuracy. Results: A total of 132 patients who met the eligible criteria and had adequate specimens for IHC confirmation were included. Pathological revised cases in poor differentiated subgroup, biopsy samples and high-level AD-TMs cases were more than those with high/moderate differentiation, surgical specimens and normal-level AD-TMs. Moreover, biopsy sample was a significant factor decreasing diagnostic accuracy of pathological subtype (OR, 4.037; 95% CI 1.446-11.267, p=0.008). Additionally, EGFR mutation rate was higher in patients with pathological diagnostic changes than those with confirmed SQCC (16.7% vs 4.4%, p=0.157). Conclusions: Diagnosis based on HE staining only might cause pathological misinterpretation in NSCLC patients with poor differentiation or high-level AD-TMs, especially those with biopsy samples. HE staining and IHC should be combined as pathological diagnostic standard. The occurrence of EGFR mutations in pulmonary SQCC might be overestimated.

Historical Long-term Exposure to Pentachlorophenol Causing Risk of Cancer - A Community Study

Zheng, Rui-Zhi,Zhang, Qing-He,He, Yi-Xin,Zhang, Qian,Yang, Lin-Shen,Zhang, Zhi-Hua,Zhang, Xiu-Jun,Hu, Jing-Ting,Huang, Fen Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Background: Pervious studies suggested occupational workers exposure to pentachlorophenol (PCP) might contribute to increased risk of cancer. However, few studies have focused on associations between PCP and cancer risk at the community level. Objective: The present study was to explore the cancer risk for the community population living long-term in a PCP contaminated area. Methods: All the cancer cases diagnosed in 2009-2011 in Tongling City were collected. The cancer patients' residencies were geo-referenced in each district. The historical PCP usage for each district of Tongling was calculated as the PCP pollution index, which was further used to divide into PCP exposure categories. Standardized rate ratios (SRRs) of cancer incidence were applied to detect the cancer risk as exposure grade elevated. Correlation analysis was performed to analyze the relationship between PCP pollution and cancer incidence. Results: A total of 5,288 cancer cases (3,451 male and 1,837 female) were identified. PCP usage was correlated with the incidence of leukemia (r=0.88, P=0.002) for males, and with cancer of the esophagus for males (r=0.83, P=0.008) and females (r=0.71, P=0.020). Compared with the low exposure category, significant SRRs for total cancer sites was obtained for high PCP exposure category (SRR=1.61, 95%CI=1.59-1.62). Most SRR values of the cancer sites were significantly increased as exposure grade elevated and exposure time extended. Conclusion: The present study found that community residents living in the PCP contaminated area had increased risk of cancers. Leukemias, lymphomas and nasopharyngeal and esophageal cancers are most possibly associated with PCP exposure.

Tas13D Inhibits Growth of SMMC-7721 Cell via Suppression VEGF and EGF Expression

He, Huai-Zhen,Wang, Nan,Zhang, Jie,Zheng, Lei,Zhang, Yan-Min Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: Taspine, isolated from Radix et Rhizoma Leonticis has demosntrated potential proctiective effects against cancer. Tas13D, a novel taspine derivative synthetized by structure-based drug design, have been shown to possess interesting biological and pharmacological activities. The current study was designed to evaluate its antiproliferative activity and underlying mechanisms. Methods: Antiproliferative activity of tas13D was evaluated by xenograft in athymic mice in vivo, and by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and cell migration assays with human liver cancer (SMMC-7721) cell lines in vitro. Docking between tas13D and VEGFR and EGFR was studied by with a Sybyl/Surflex module. VEGF and EGF and their receptor expression was determined by ELISA and real-time PCR methods, respectively. Results: Our present study showed that tas13D inhibited SMMC-7721 xenograft tumor growth, bound tightly with the active site of kinase domains of EGFR and VEGFR, and reduced SMMC-7721 cell proliferation (IC=34.7 ${\mu}mol/L$) and migration compared to negative controls. VEGF and EGF mRNAs were significantly reduced by tas13D treatment in a dose-dependent manner, along with VEGF and EGF production. Conclusion: The obtained results suggest that tas13D inhibits tumor growth and cell proliferation by inhibiting cell migration, downregulating mRNA expression of VEGF and EGF, and decreasing angiogenic factor production. Tas13D deserves further consideration as a chemotherapeutic agent.

Control of Molecular Weight Distribution for Polypropylene Obtained by Commercial Ziegler-Natta Catalyst: Effect of Electron Donor

He-Xin Zhang,윤근병,이영주,박준려,이동호 한국고분자학회 2011 Macromolecular Research Vol.19 No.6

Polymerization of propylene was carried out using a MgCl_2-supported TiCl_4 catalyst in conjunction with triethylaluminium (TEA) as the cocatalyst and various types of alkoxy silane compounds as an external donor. The effect of the external donor on the performance of the catalyst with different internal donors was investigated. The polydispersity index (PDI) of polypropylene (PP) obtained with the diether and succinate based catalyst were decreased with the introduction of an external donor and the PDI increased for the phthalate based catalyst. The molecular weight and PDI increased with the introduction of an external donor. The highest PDI of PP was obtained by polymerization with di-n-propyldimethoxysilane (DnPDMS) as an external donor. In addition, a mixture of external donors was used to control the PDI of PP and the composition of the catalyst was examined after treated with TEA/external donor. Furthermore, the theoretical PDI value was calculated for a mixture of external donor systems. The PDI of PP could be controlled and predicted while retaining high activity, high isospecificity and high molecular weight by changing the structure of the external donor and/or their mixture.