44 results on '"Zhang Junxi"'
Search Results
2. Structurally Modulated Na4–xFe3–xVx(PO4)2P2O7 by Vanadium Doping for Long-Life Sodium-Ion Batteries.
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Zhang, Hao, Cao, Yongjie, Liu, Zhaolu, Cheng, Xinsheng, Li, Xun-Lu, Xu, Jie, Wang, Nan, Yang, Hui, Liu, Yao, and Zhang, Junxi
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- 2024
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3. Towards High-Performance Sodium-Ion Batteries via the Phase Regulation Strategy.
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Liu, Zhaolu, Cao, Yongjie, Zhang, Hao, Xu, Jie, Wang, Nan, Zhao, Deqiang, Li, Xunlu, Liu, Yao, and Zhang, Junxi
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- 2024
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4. Coherent Random Lasing Realized in Polymer Vesicles
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Li, Yaxin, Xie, Kang, Zhang, Xiaojuan, Hu, Zhijia, Ma, Jiajun, Chen, Xianxian, Zhang, Junxi, Liu, Zhenming, and Chen, Dong
- Abstract
We have demonstrated the realization of a coherent vesicle random lasing (VRL) from the dye doped azobenzene polymer vesicles self-assembled in the tetrahydrofuran-water system, which contains a double-walled structure: a hydrophilic and hydrophobic part. The effect of the dye and azobenzene polymer concentration on the threshold of random laser has been researched. The threshold of random laser decreases with an increase in the concentration of the pyrromethene 597 (PM597) laser and azobenzene polymer. Moreover, the scattering of small size group vesicles is attributed to providing a loop to boost the coherent random laser through the Fourier transform analysis. Due to the vesicles having the similar structure with the cell, the generation of coherent random lasers from vesicles expand random lasers to the biomedicine filed.
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- 2024
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5. Converting Layered Zinc Acetate Nanobelts to One-dimensional Structured ZnO Nanoparticle Aggregates and their Photocatalytic Activity
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Zhang, Ye, Zhu, Feng, Zhang, Junxi, and Xia, Lingli
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Abstract: We were successful in synthesizing periodic layered zinc acetate nanobelts through a hydrothermal solution process. One-dimensional structured ZnO nanoparticle aggregate was obtained by simple thermal annealing of the above-mentioned layered ZnO acetate nanobelts at 300 °C. The morphology, microstructure, and composition of the synthesized ZnO and its precursors were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and infrared spectroscopy, respectively. Low angle X-ray diffraction spectra reveal that as-synthesized zinc acetate has a layered structure with two interlayer d-spacings (one is 1.32 nm and the other is 1.91 nm). SEM and TEM indicate that nanobelt precursors were 100–200 nm in width and possesses length up to 30 μm. Calcination of precursor in air results in the formation of one-dimensional structured ZnO nanoparticle aggregates. In addition, the as-prepared ZnO nanoparticle aggregates exhibit high photocatalytic activity for the photocatalytic degradation of methyl orange (MO).
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- 2024
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6. Modulation for RuO2/TiO2 via Simple Synthesis to Enhance the Acidic Oxygen Evolution Reaction.
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Zhang, Junxi, Lin, Rui, Zhao, Yichen, Wang, Hong, Liu, Shengchu, and Cai, Xin
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- 2023
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7. Low-Cost, High-Energy Na-Ion Hybrid Supercapacitors.
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Liu, Zhaolu, Cao, Yongjie, Zhang, Hao, Xu, Jie, Zhao, Deqiang, Wang, Nan, Cheng, Guangyu, Zhou, Yirong, Liu, Yao, and Zhang, Junxi
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- 2022
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8. Tunable replica symmetry breaking in random laser
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Xia, Jiangying, Zhang, Xiaojuan, Zhou, Kaiming, Zhang, Lin, Wang, Erlei, Du, Wenyu, Ma, Jiajun, Li, Siqi, Xie, Kang, Yu, Benli, Zhang, Junxi, and Hu, Zhijia
- Abstract
Replica symmetry breaking (RSB) has been widely recognized as a statistical analysis approach to understand the disorder and nonlinear interactions in complex systems ranging from atoms to the cosmic scale. However, it is challenging to analyze the nonlinear optical characteristics of random laser (RL) in disordered gain medium via RSB due to the lack of a general RSB-based statistical analysis framework. In this work, we report the tunable RSB in polymer fiber RL, where the effects of temperature and different structures on RSB are investigated experimentally and theoretically. It experimentally proves that RSB in RL is not robust, and disorder and temperature are responsible for tunable RSB in RL, which contributes to the improvement of the statistical analysis framework for investigating the optical principles of RL using RSB. And the finding of the tunable RSB allows to investigate the dynamical differences for various RL systems, which broadens the directions for the use of spin-glass theory to explore the physical mechanism of RL.
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- 2023
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9. Iron‐Based Sulfate for Sodium‐Ion Batteries: Past, Present, and Future
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Liu, Zhaolu, Wang, Ning, Wang, Ruiqi, Xu, Jie, Zhang, Hao, Wang, Nan, Cao, Yongjie, Liu, Yao, and Zhang, Junxi
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Sodium‐ion batteries (SIBs) are crucial energy equipment that sustain low cost and better environmental benefit. Nevertheless, the practical energy density of SIBs is limited by cathode material. Over last decades, the iron‐based sulfate (IBS) has been extensively studied owing to its numerous advantages, including a large theoretical specific energy (over 100 Wh kg−1), high working potential (above 3.4 V), low cost, good structural stability, and environmental friendliness. Nevertheless, the application of IBS in SIBs is limited by its unsuitable electrolyte and low electronic/ionic conductivity. This review summarizes recently developed results on IBS materials for SIBs, ranging from the phase diagram–composition structure–electrochemical performance to modification research. A generalized summary of the future prospects of IBS‐based materials is also provided, with the hope of inspiring further advances in their application in SIBs. This article comprehensively reviews the research progress and potential development prospects of iron‐based sulfate from the perspective of phase diagram–composition–structure.
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- 2024
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10. Stable and tunable single-mode lasers based on cholesteric liquid crystal microdroplets
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Shi, Jianzhou, Ma, Chao, Ren, Mingyan, Xu, Miao, Zhu, Jun, Qiu, Longzhen, Ding, Yunsheng, Zhang, Junxi, and Lu, Hongbo
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Although many studies on cholesteric liquid crystal (CLC) microdroplet single-mode lasers are available, it has been shown that the stability and tunability of such microdroplets are difficult to achieve simultaneously. In this paper, a new, to the best of our knowledge, method is proposed for the mass and rapid preparation of stable and tunable monodisperse CLC microdroplet single-mode lasers. This is based on the formation of polymer networks on the surface of the microdroplet via interfacial polymerization and a disruption of the orderliness of the polymer networks by increasing the temperature during polymerization, which results in a single pitch inside the microdroplets. This approach enables CLC microdroplet single-mode lasers to achieve improved environmental robustness, while maintaining the same temperature tunability as the unpolymerized sample. Our method has promising future applications in integrated optics, flexible devices, and sensors.
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- 2022
11. Christiansen filters realized with cylindrical lenses of even symmetry
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Xie, Kang, Ma, Dianguo, Ma, Ji, Liang, Lanju, Wei, Dequan, Wang, Xueqin, Wang, Meng, Hu, Zhijia, Zhang, Junxi, and Mao, Qiuping
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A type of Christiansen filter that takes the form of a smooth cylindrical lens of even symmetry is proposed. By varying the shape of the lens, the filter can be made to realize many common filtering responses, including the polynomial function response, the Gaussian function response, and the sinc function response. A systematic design technique based on inverse scattering is established, and a desired, prescribed response can be tailored by properly shaping the lens of the filter. Three prototypical Christiansen filters, namely, a second-order all-real-roots filter, a second-order sinc filter, and a Gaussian filter, are synthesized using the proposed method. A prescribed response at 545 nm with a FWHM of 2 nm is achieved systematically by all of the three Christiansen filters.
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- 2022
12. U-shaped relationship between ozone exposure and preterm birth risk associated with preconception telomere length.
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Zhou, Guoyu, Chai, Jian, Li, Qinyang, Sun, Panpan, Wang, Yalong, Wu, Jingjing, Zhang, Junxi, Li, Yan, Dong, Wei, Zhang, Cuican, Yu, Fangfang, Yan, Xi, and Ba, Yue
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TELOMERES ,OZONE ,AIR pollutants ,PERIODIC health examinations ,ENVIRONMENTAL monitoring ,PREMATURE labor - Abstract
There are conflicting findings regarding the association of ozone (O 3) exposure with preterm birth (PTB) occurrence. In the present study, two cohorts were combined to explore the relationship between maternal O 3 exposure during pregnancy and PTB risk, and analyze the underlying mechanisms of this relationship in terms of alterations in the preconception telomere length. Cohort 1 included mothers who participated in the National Free Preconception Health Examination Project in Henan Province from 2014 to 2018 along with their newborns (n = 1,066,696). Cohort 2 comprised mothers who conceived between 2016 and 2018 and their newborns (n = 1871) from six areas in Henan Province. The telomere length was assessed in the peripheral blood of mothers at the preconception stage. Data on air pollutant concentrations were collected from environmental monitoring stations and individual exposures were assessed using an inverse distance-weighted model. O 3 concentrations (100.60 ± 14.13 μg/m
3 ) were lower in Cohort 1 than in Cohort 2 (114.09 ± 15.17 μg/m3 ). Linear analyses showed that PTB risk decreased with increasing O 3 exposure concentrations in Cohort 1 but increased with increasing O 3 exposure concentrations in Cohort 2. Nonlinear analyses revealed that PTB risk tended to decrease and then increase with increasing O 3 exposure concentrations in both cohorts. Besides, PTB risk was reduced by 88% for each-unit increase in telomere length in those exposed to moderate O 3 concentrations (92.4–123.7 μg/m3 , P < 0.05). While no significant association was observed between telomere length and PTB at extreme O 3 concentration exposure during entire pregnancy (<92.4 or >123.7 μg/m3 , P > 0.05) in Cohort 2. These findings reveal a nonlinear (U-shaped) relationship between O 3 exposure and PTB risk. Furthermore, telomere with elevated length was associated with decreased risk of PTB only when exposed to moderate concentrations of O 3 , but not when exposed to extreme concentrations of O 3 during pregnancy. [Display omitted] • There was a U-shaped relationship between O 3 exposure and preterm birth (PTB) risk. • In the moderate range, O 3 did not have a positive association with PTB risk. • Telomere length was involved in the U-shaped relationship between O 3 and PTB. • Telomere length was associated with decreased PTB risk for moderate O 3 exposures. [ABSTRACT FROM AUTHOR]- Published
- 2024
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13. Preconception alcohol consumption and risk of miscarriage in over 4.5 million Chinese women aged 20–49 years
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Chai, Jian, Guo, Tonglei, Deng, Yuzhi, Jiang, Lifang, Zhang, Junxi, Xu, Qin, Peng, Zuoqi, He, Yuan, Wang, Yuanyuan, Zhang, Ya, Zhang, Hongguang, Wang, Qiaomei, Shen, Haiping, Zhang, Yiping, Yan, Donghai, Yang, Ying, and Ma, Xu
- Abstract
ObjectiveTo assess the impact of preconception alcohol consumption on risk of miscarriage incidence, and further evaluate the association between maternal periconception drinking abstinence and miscarriage.MethodsWe performed a population-based, retrospective cohort study in China between 1 January 2013 and 31 December 2016. Alcohol intake and potential confounding factors were reported in standard questionnaires. Participants who became pregnant were recontacted for pregnancy outcome information within 1 year. A total 4 531 680 women with available data on preconception alcohol intake and miscarriage were included in the final analyses. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).ResultsThe prevalence of miscarriage was 2.70% among 4 531 680 women. Compared with non-drinkers, the adjusted OR of miscarriage was 1.06 (95% CI 1.02 to 1.10) and 1.59 (95% CI 1.15 to 2.20) in maternal occasional drinkers and regular drinkers, respectively. Compared with couples in which neither the male nor the female consumed alcohol, the adjusted OR for miscarriage among women was 1.09 (95% CI 1.07 to 1.10), 1.13 (95% CI 1.06 to 1.21) and 1.12 (95% CI 1.07 to 1.17) in the couples in which only the female drank alcohol, only the male drank alcohol, and both drank alcohol, respectively. The adjusted OR was 0.58 (95% CI 0.51 to 0.65) in women with alcohol abstinence compared with alcohol drinkers.ConclusionsPreconception alcohol consumption was associated with higher odds of miscarriage, and an increasing risk was found with paternal and maternal alcohol drinking. Periconception alcohol abstinence was inversely associated with miscarriage.
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- 2022
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14. Tunable multi-mode laser based on robust cholesteric liquid crystal microdroplet
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Lu, Hongbo, Shi, Jianzhou, Wang, Qi, Xue, Yingying, Yang, Le, Xu, Miao, Zhu, Jun, Qiu, Longzhen, Ding, Yunsheng, and Zhang, Junxi
- Abstract
To date, various studies have been dedicated to the development of cholesteric liquid crystal (CLC) microdroplet omnidirectional lasers. In this work, a stable and tunable multi-mode laser emission is achieved by designing a dye-doping CLC microdroplet. In such a structure, the polymer network only exists on the surface, maintaining stability while providing tunability, and due to the uneven distribution of the pitch, it leads to multi-mode laser emission. A large number of microdroplets are produced quickly via a new method based on ultrasonic separation. During the reaction, we introduce interfacial polymerization where monomers and photoinitiator are respectively distributed inside and outside the microdroplets through mutual diffusion, which enables one to make the polymer network exist on the surface instead of the interior. The obtained microdroplet-based multi-mode laser is shown to possess stability and tunability, demonstrating a great potential for flexible devices and 3D displays.
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- 2021
15. Waveguided nematic liquid crystal random lasers
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Huang, Yunxi, Zhang, Xiaojuan, Yu, Benli, Ma, Jiajun, Xie, Kang, Cheng, Sheng, Zhang, Junxi, and Hu, Zhijia
- Abstract
In waveguided nematic liquid crystal random lasers (NLCRLs), we realize polarized random laser (RL) emission and discover that the waveguide effect reduces the transmission loss of the RL whose polarization is parallel to the liquid crystal molecules (LCMs). Compared with the traditional liquid crystal random lasers, the waveguide NLCRLs can achieve the regulation of RLs strength, polarization, and wavelength in the same structure. The electric field can drive the rotation of LCMs to control the RL polarization and intensity. The drop of horizontal polarization laser and the increase of vertical polarization laser prove the role of the waveguide effect. In addition, the disorder of the waveguided NLCRLs is highly sensitive to temperature, which makes it easy to control the wavelength and intensity of the RL. As the temperature rises, the waveguide effect is weakened, resulting in a weakening of the restriction along liquid crystal (LC) cell normal direction. The reduced laser intensity verifies the role of the waveguide effect.
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- 2021
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16. A New Polyanion Na3Fe2(PO4)P2O7 Cathode with High Electrochemical Performance for Sodium-Ion Batteries.
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Cao, Yongjie, Yang, Chen, Liu, Yao, Xia, Xiuping, Zhao, Deqiang, Cao, Yuanjie, Yang, Haishen, Zhang, Junxi, Lu, Jing, and Xia, Yongyao
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- 2020
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17. Application of Terahertz Spectroscopy and Imaging in the Diagnosis of Prostate Cancer
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Zhang, Ping, Zhong, Shuncong, Zhang, Junxi, Ding, Jian, Liu, Zhenxiang, Huang, Yi, Zhou, Ning, Nsengiyumva, Walter, and Zhang, Tianfu
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The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.
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- 2020
18. Resonance modes of plasmonic nanorod metamaterials and their applications
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Zhou, Zhiping, Yuan, Xiao-Cong, Dai, Daoxin, Zhang, Junxi, Hu, Zhijia, Xie, Kang, Wei, Yongqin, Wang, Haoyu, Wang, Fei, Liang, Taiming, Ghafoor, Sonia, Wang, Pei, Fei, Guangtao, Zhang, Lide, and Zhang, Lin
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- 2019
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19. Resemblance in Corrosion Behavior of Selective Laser Melted and Traditional Monolithic β Ti-24Nb-4Zr-8Sn Alloy.
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Qin, Peng, Chen, Yang, Liu, Yu-Jing, Zhang, Junxi, Chen, Liang-Yu, Li, Yuhua, Zhang, Xuhui, Cao, Chongde, Sun, Hongqi, and Zhang, Lai-Chang
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- 2019
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20. Chemical Synthesis of Conjugation-Ready Trisaccharides Corresponding to Biological Repeating Units of Pseudomonas aeruginosaSerotype 10 and 19 O-Antigens
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Zou, Xiaopeng, Qin, Chunjun, Tian, Guangzong, Zhang, Junxi, Hu, Jing, and Yin, Jian
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Here we report the chemical synthesis of conjugation-ready trisaccharides, representing biological repeating units of Pseudomonas aeruginosaserotype 10 and 19 O-antigens. The α-d-QuiN3glycosidic bond was stereoselectively synthesized through TMSI─Ph3P═O mediated 1,2-cisglycosylation. Selective oxidation of the C6–OH group at the disaccharide stage allowed for benzylidene-promoted construction of the α-l-GalN3glycosidic bond and simplification of the postglycosylation process at the trisaccharide stage. The low reaction temperature and neighboring electron-donating effect facilitated the efficient synthesis of the trisaccharide.
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- 2024
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21. Eco-Friendly Sustainable and Responsive High-Performance Benzotriazole-Metal Organic Frameworks/Silica Composite Coating with Active/Passive Corrosion Protection on Copper
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Gao, Xu, Gao, Yan, Cao, Huaijie, and Zhang, Junxi
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Coatings with only passive protection cannot offer long-term anticorrosion on metals. Eco-friendly sustainable and responsive coating for active/passive corrosion protection is desirable to extend the service life of metals. Here, benzotriazole (BTA)-metal organic frameworks (Cu-MOFs, UiO-66) were embedded in silica (SiO2) coating by one-step electrodeposition on copper. Combined with passive capability of MOFs and active protection of BTA inhibitor, the composite coating (BTA-MOF/SiO2) exhibited high and stable corrosion resistance, confirmed by microstructure characterizations and electrochemical tests. As a result, the as-prepared composite coating exhibited superhydrophobicity with a water contact angle of 154.2°. With loading of BTA-MOF in SiO2coating, the impedance modulus at 0.01 Hz increased by ∼10-fold and the corrosion current density decreased to 3.472 × 10–9A·cm–2. Immersion and salt spray tests confirmed the long-term protection of the composite coating. The responsive release of BTA inhibitor endows the coating with a responsively anticorrosive behavior. The active-passive ability makes the coating a good candidate for protection on metals used in highly salty environments.
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- 2024
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22. Resemblance in Corrosion Behavior of Selective Laser Melted and Traditional Monolithic β Ti-24Nb-4Zr-8Sn Alloy
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Qin, Peng, Chen, Yang, Liu, Yu-Jing, Zhang, Junxi, Chen, Liang-Yu, Li, Yuhua, Zhang, Xuhui, Cao, Chongde, Sun, Hongqi, and Zhang, Lai-Chang
- Abstract
Distinct corrosion behavior was reported in multiphased titanium alloys prepared by additive manufacturing and by traditional technologies because of different phase constituents formed during processing. An open question is therefore raised: is there always different corrosion behavior of materials prepared by different methods? This work reports resemble corrosion behavior of selective laser melted and wrought single β-phase Ti-24Nb-4Zr-8Sn (Ti2448) in both NaCl solution and Hank’s solution. The electrochemical measurements showed that both samples have close calculated polarization resistance and corrosion potential in NaCl solution, i.e., 4.99 ± 0.63 MΩ cm2and −0.26 ± 0.01 V for the selective laser-melted Ti2448, and 4.42 ± 0.71 MΩ cm2and −0.25 ± 0.01 V for the wrought Ti2448, respectively. Both samples reveal the same variation in weight change after 180-day immersion test in Hank’s solution. Such resemblance in corrosion behavior without pitting morphologies is attributed to the formation of monolithic β-phase during processing, which demonstrates that titanium alloys with single phase show comparable corrosion behavior regardless of the manufacturing methods adopted.
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- 2019
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23. The spread of antibiotic resistance to humans and potential protection strategies.
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Ding, Dong, Wang, Bin, Zhang, Xiaoan, Zhang, Junxi, Zhang, Huanhuan, Liu, Xinxin, Gao, Zhan, and Yu, Zengli
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DRUG resistance in bacteria ,ANTIBIOTIC residues ,HORIZONTAL gene transfer ,COLONIZATION (Ecology) - Abstract
Antibiotic resistance is currently one of the greatest threats to human health. Widespread use and residues of antibiotics in humans, animals, and the environment can exert selective pressure on antibiotic resistance bacteria (ARB) and antibiotic resistance gene (ARG), accelerating the flow of antibiotic resistance. As ARG spreads to the population, the burden of antibiotic resistance in humans increases, which may have potential health effects on people. Therefore, it is critical to mitigate the spread of antibiotic resistance to humans and reduce the load of antibiotic resistance in humans. This review briefly described the information of global antibiotic consumption information and national action plans (NAPs) to combat antibiotic resistance and provided a set of feasible control strategies for the transmission of ARB and ARG to humans in three areas including (a) Reducing the colonization capacity of exogenous ARB, (b) Enhancing human colonization resistance and mitigating the horizontal gene transfer (HGT) of ARG, (c) Reversing ARB antibiotic resistance. With the hope of achieving interdisciplinary one-health prevention and control of bacterial resistance. Antibiotic consumption is overall on a downward trend, but still at a high level. ARG and ARB in humans have a wide range of environmental sources. Anti-colonization, mitigation of transmission and re-sensitization can be strategies to control antibiotic resistance. Dietary nutritional interventions can be a viable approach to inhibit ARG colonization and transmission in humans. [ABSTRACT FROM AUTHOR]
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- 2023
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24. The transition from incoherent to coherent random laser in defect waveguide based on organic/inorganic hybrid laser dye
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Xia, Jiangying, Xie, Kang, Ma, Jiajun, Chen, Xianxian, Li, Yaxin, Wen, Jianxiang, Chen, Jingjing, Zhang, Junxi, Wu, Sizhu, Cheng, Xusheng, and Hu, Zhijia
- Abstract
This paper systematically demonstrated a variety of experimental phenomena of random lasers (RLs) of N,N′-di-(3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl) perylene diimide (DPP) organic/inorganic hybrid laser dye, which is composed of perylene diimide (PDI) as gain media and polyhedral oligomeric silsesquioxanes (POSS) as scattering media at a mole ratio of 1:2. In this work, we observe the transition from incoherent RL in the DPP-doped solutions and polymer membrane systems using dip-coating method to coherent RL in the polymer membrane system with defect waveguide using semi-polymerization (SP) coating method. Meanwhile, we found that the hybrid dye-DPP has a long lasing lifetime compared with the traditional laser dyes, which indicates that the POSS group can suppress the photo-bleaching effect to extend the working life of laser dyes.
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- 2018
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25. Simulation of high performance GaN/InGaN heterojunction phototransistor
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Jin, Weiqi, Li, Ye, Zhang, Junxi, Wang, Yidong, and Chen, Jun
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- 2018
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26. Influence of Direct Current Electric Field on Electrode Process of Carbon Steel under Thin Electrolyte Layers
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Chen, Yang, Yang, Yan, Zhang, Junxi, Zhang, Xin, Dai, Nianwei, and Zhang, Chang
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Although the corrosion behavior of metals under thin electrolyte layers (TELs) has been widely studied, little is understood about the electrode processes under these layers and even less so when exposed to a direct current (DC) electric field. This work shows that the open circuit potential (OCP) shifts negatively, the current density of oxygen reduction increases and initial hydrogen evolution potential shifts positively with enhancing the DC electric field intensity. The OCP shifts positively under the polarity reversal of DC electric field. The area covered with corrosion product decreases with increasing DC electric filed intensity. All these results indicate that the applied DC electric filed promotes the corrosion resistance of carbon steel. The synergistic effect of electric field on the electrode process of TELs has also been discussed in depth.
- Published
- 2018
27. Green space, air pollution and gestational diabetes mellitus: A retrospective cohort study in central China.
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Yu, Zengli, Feng, Yang, Chen, Yao, Zhang, Xiaoan, Zhao, Xin, Chang, Hui, Zhang, Junxi, Gao, Zhan, Zhang, Huanhuan, and Huang, Cunrui
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GESTATIONAL diabetes ,NORMALIZED difference vegetation index ,AIR pollution ,AIR pollutants ,COHORT analysis - Abstract
Emerging evidence suggests residential surrounding green space is beneficial for human health. The association between green space and GDM showed inconsistent results, and potential effect modification of green space with air pollution is still unclear. This study aims to evaluate the association between green space and GDM, and further explore potential interaction and medication effects. Participants were recruited from a retrospective cohort study between 2015 and 2020 in Henan, China. Residential green space based on normalized difference vegetation index (NDVI) and air pollution exposure were estimated using spatial-statistical models. Multivariate logistic regression was applied to evaluate the association between per 0.1 unit increase in NDVI with 4 buffer sizes (250 m, 500 m, 1000 m, 2000 m) and GDM. We examined potential interaction of green space and air pollutants on GDM. Mediating effects of air pollution associated with green space exposure on GDM were also investigated by causal mediation analyses. A total of 46,665 eligible pregnant women were identified. There were 4092 (8.8 %) women diagnosed with GDM according to the IADPSG criteria. We found that per 0.1-unit increment in NDVI 250 m , NDVI 500 m , NDVI 1000 m and NDVI 2000 m in second trimester were associated with the decreased risk of GDM, with adjusted OR of 0.921(95 %CI: 0.890–0.953), 0.922 (95 %CI: 0.891–0.953), 0.921 (95 %CI: 0.892–0.952) and 0.921 (95 %CI: 0.892–0.951), respectively. We identified significant interactions between second trimester PM 2.5 and O 3 exposure and NDVI for GDM (P interaction < 0.001). The causal mediation analysis showed that PM 2.5 mediated approximately 2.5–5.5 % of the association between green space and GDM, while the estimated mediating effect of O 3 was approximately 30.1–38.5 %. In conclusion, our study indicates that residential green space was associated with a reduced risk of GDM, particularly second trimester. Green space may benefit to GDM partly mediated by a reduction in PM 2.5 and O 3. [Display omitted] • The association of residential green space with the risk of GDM were explored. • We found second trimester green space were associated with a reduced risk GDM. • Green space may benefit to GDM partly mediated by a reduction in PM 2.5 and O 3. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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28. A chaotic time series prediction model for speech signal encoding based on genetic programming.
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Yang, Lei, Zhang, Junxi, Wu, Xiaojun, Zhang, Yumei, and Li, Jingjing
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CHAOS theory ,TIME series analysis ,SPEECH processing systems ,SIGNAL processing ,ENCODING ,GENETIC programming - Abstract
In this paper, a novel solving method for speech signal chaotic time series prediction model was proposed. A phase space was reconstructed based on speech signal's chaotic characteristics and the genetic programming (GP) algorithm was introduced for solving the speech chaotic time series prediction models on the phase space with the embedding dimension m and time delay τ . And then, the speech signal's chaotic time series models were built. By standardized processing of these models and optimizing parameters, a speech signal's coding model of chaotic time series with certain generalization ability was obtained. At last, the experimental results showed that the proposed method can get the speech signal chaotic time series prediction models much more effectively, and had a better coding accuracy than linear predictive coding (LPC) algorithms and neural network model. [ABSTRACT FROM AUTHOR]
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- 2016
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29. Heat Treatment Degrading the Corrosion Resistance of Selective Laser Melted Ti-6Al-4V Alloy
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Dai, Nianwei, Zhang, Junxi, Chen, Yang, and Zhang, Chang
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Ti-6Al-4V alloy produced by selective laser melting (SLM) was reported to exhibit an inferior corrosion resistance compared with the traditionally processed Grade 5 alloy, due to the formation of high-energy metastable a' martensite with regard to a martensite. This work manipulates the transformation of a' martensite to a martensite by heat-treatment in SLM-produced Ti-6Al-4V alloy and studies the effect on its corrosion behavior using electrochemical tests and microstructural analysis. The electrochemical results reveal that the heat-treated SLM-produced samples exhibit a higher corrosion rate than the as-received counterparts. The microstructural characterization results show that the acicular a' martensite vanishes gradually, and a plate-shaped a phase and a lamellar a + b mixture continuously form with enhancing heat-treatment temperature, which increases the grain size. The relation between changes in grain size and corrosion resistance of SLM-produced Ti-6Al-4V has been discussed in detail.
- Published
- 2017
30. Acoustic Model for Leak Detection of Water Supply Pipeline
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Zhang, Lingchun, Jiang, Haiming, Zhang, Junxi, Chen, Haitao, Lu, Haimin, Li, Jianquan, Hu, Zhijia, and Xie, Kang
- Published
- 2023
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31. Size and dielectric-environment dependence of transversal resonance modes of localized surface plasmons in silver nanorods
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Yu, Jie, Zhang, Junxi, Zhang, Lide, Jia, Junhui, Xu, Wei, Wang, Junfeng, and Fei, Guangtao
- Abstract
Tuning transversal resonance modes of localized surface plasmons (LSPs) by the size and the ambient dielectric medium of Ag nanorods is presented. It is found that the resonance wavelength and intensity of the transversal modes of LSPs are closely related to the dimensions of the Ag nanorods embedded in anodic aluminum oxide membranes. The transversal resonance peak exhibits obvious redshifts from 365 to 396 nm with increasing nanorod diameter from 40 to 80 nm, and the resonance intensity remarkably enhances with increasing nanorod diameter. In addition, it is observed that the transversal resonance modes of LSPs in Ag nanorods are strongly sensitive to their surrounding dielectric medium such as water, ethanol, and cetyltrimethylammonium bromide, and the transversal resonance peak distinctly redshifts from 422 to 467 nm when the refractive index of the dielectric medium increases from 1.342 to 1.435. As a result, a refractive index sensitivity of up to 484 nm/RIU can be achieved based on the transversal resonance modes. The transverse resonance modes of LSPs in the Ag nanorods can be used for sensitive quantification of chemical and biological species.
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- 2016
32. Fibre Bragg gratings fabrication in four core fibres
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Kalli, Kyriacos, Mendez, Alexis, Wang, Changle, Yan, Zhijun, Sun, Qizhen, Sun, Zhongyuan, Mou, Chengbo, Zhang, Junxi, Badmos, Abdulyezir, and Zhang, Lin
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- 2016
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33. Temperature Sensitivity of Polymer Fiber Microlasers
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Wang, Chun, Zhang, Xiaojuan, Ma, Jiajun, Xie, Kang, Zhang, Junxi, and Hu, Zhijia
- Abstract
There are many kinds of materials or methods used to make optical microcavities, and they have many different geometric structures. And electrospinning technique has become a very convenient and easy one to prepare polymer fiber. Based on this situation, PM597-doped polymer solution was prepared into high-performance fibers with different diameters by electrospinning technology in our work. In order to better study the temperature sensing of polymer fiber whispering gallery mode, we have placed it on two different substrates with gold and aluminum. A 532 nm pulsed laser beam was used to excite a single fiber in the radial direction, then the whispering gallery mode (WGM) laser was observed and the distribution of WGM was determined by theoretical calculations. The threshold of samples on aluminum substrate is 0.4 μJ. In addition, it is found that the samples on aluminum substrate performed better in temperature sensing, and the value is 0.13 nm/°C. As a result, WGM polymer fiber microcavities on aluminum substrate made by electrospinning technology have very broad development prospects in biosensing, optical pump lasers and other applications.
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- 2022
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34. Highly Efficient, Irreversible and Selective Ion Exchange Property of Layered Titanate Nanostructures
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Li, Nian, Zhang, Lide, Chen, Yongzhou, Fang, Ming, Zhang, Junxi, and Wang, Huimin
- Abstract
Layered titanates (Na2Ti3O7·nH2O) with exchangeable sodium cations located in the interlayer have been synthesized by simple hydrothermal treatment of Ti precursor in concentrated NaOH solutions. By proper control of the synthesis conditions, different morphologies of nanofibers and nanosheets are obtained. The metastable layered structure of the titanates collapses during the ion exchange, resulting in irreversible ion exchange. Target cations (eg., Ag+, Cu2+, Pb2+and Eu3+) are completely concentrated from water and then tightly immobilized in the interlayer which is of great significance for the removal and subsequent safe disposal of hazardous metal cations. The ion exchange of the nanosheets is much more efficient than that of the nanofibers and other inorganic ion exchangers due to the larger surface area, less stable layered structure and larger amount of interlayer water of the nanosheets. The ion exchange of the titanates is also very selective. Valence, hardness, and radius of cations are main factors affecting the selectivity. Cations trapped in the interlayer are released by an acid‐induced phase transformation of the titanate nanosheets to rutile. Then the rutile can be used as a new Ti precursor to synthesize the titanate nanostructures, resulting in a full cycle of material use. The nanosheets may find applications in the decontamination and safe disposal of radioactive and heavy metal cations and also in the collection of valuable cations from water.
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- 2012
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35. Endogenous Markups, Intensity of Competition, and Persistence of Business Cycles
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Zhang, Junxi
- Abstract
In order to study the propagation mechanism of business cycles, in particular to investigate how the intensity of competition affects market structure and output persistence over business cycles, this paper presents a real business‐cycle model with imperfect competition and increasing returns to scale. This analysis considers the markups of price over cost to be endogenous. With endogenous markups, two standard forms of oligopolistic competition—Bertrand and Cournot—are considered. Results show that: (1) the propagation mechanism in the sense of output persistence is greater under Cournot; (2) the propagation mechanism is unequivocally greater with imperfect competition, regardless of whether markups are endogenous or not; and (3) under imperfect competition, the propagation mechanism is greater with endogenous markups than with exogenous markups. Overall, these results suggest that more intense competition produces lower persistence in output growth and, thus, a weaker propagation mechanism. In a calibration exercise, these differences were also found to be quantitatively important.
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- 2007
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36. Microarrays of silver nanowires embedded in anodic alumina membrane templates: size dependence of polarization characteristics
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Zhang, Junxi, Yan, Youguo, Cao, Xueli, and Zhang, Lide
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Polarization characteristics of microarrays of silver nanowires embedded in an anodic alumina membrane are theoretically investigated. The microarrays mainly transmit the p-polarized wave, whereas they strongly attenuate the s-polarized wave in the near- and mid-infrared spectral range. We show that the sizes (e.g., diameter, spacing, and ratio of diameter to spacing) of the nanowires strongly affect the optical losses for the polarized waves. It is predicted that large extinction ratios and small insertion losses can be simultaneously achieved by an appropriate choice of the ratio and the diameter. An optimized design of a nanowire grid polarizer at near- and mid-infrared wavelengths is presented.
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- 2006
37. The role of maternal methylation in the association between prenatal meteorological conditions and neonatal H19/H19-DMR methylation.
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Yang, Meng, He, Tongkun, Jiang, Lifang, Wang, Hao, Zhang, Junxi, Chai, Jian, Li, Zhiyuan, Zhang, Yawei, Zhou, Guoyu, and Ba, Yue
- Subjects
METHYLATION ,CORD blood ,HIGH-income countries ,LOW-income countries ,DISEASE susceptibility - Abstract
Meteorological conditions during pregnancy can affect birth outcome, which has been linked to the H19 / H19 -differentially methylated region (DMR). However, the detailed mechanisms underlying this association are unclear. This was investigated in the present study to provide epidemiological evidence for elucidating the pathogenesis of adverse birth outcomes. A total of 550 mother-newborn pairs were recruited in Zhengzhou, China from January 2010 to January 2012. Meteorological data including temperature (T), relative humidity (RH), and sunshine duration (SSD) were obtained from the China Meteorological Data Sharing Service System. Bisulfite sequencing PCR was performed to determine the methylation levels of H19 / H19 -DMR using genomic DNA extracted from maternal peripheral and umbilical cord blood. The results showed that H19 -DMR methylation status in cord blood was positively associated with that in maternal blood. Neonatal H19 -DMR methylation was negatively associated with T and RH during the first trimester and positively associated with these variables during the third trimester. There was a positive correlation between neonatal H19 -DMR methylation and SSD during the second trimester and a negative correlation during the third trimester. Similar associations were observed between maternal H19 -DMR methylation and prenatal meteorological conditions. We also observed significant interaction effects of maternal H19 / H19 -DMR methylation and most prenatal meteorological factors on neonatal methylation, and found that changes in the methylation status of maternal H19 -DMR were responsible for the effects of prenatal meteorological conditions on neonatal methylation. In summary, neonatal H19 -DMR methylation was significantly associated with prenatal meteorological conditions, which was modified and mediated by maternal H19 -DMR methylation changes. These findings provide insights into the relationship between meteorological factors during pregnancy and adverse birth outcomes or disease susceptibility in offspring, and can serve as a reference for environmental policy-making. • Prenatal meteorological factors affect H19 -DMR methylation in mothers and newborns. • Weather changes in the 1st and 3rd trimester of pregnancy alter methylation status. • Methylation status in cord blood is positively related to that in maternal blood. • Maternal methylation modifies the effects of meteorology on neonatal methylation. [ABSTRACT FROM AUTHOR]
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- 2020
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38. A simple endogenous growth model with endogenous fertility: Indeterminacy and uniqueness
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Yip, Chong K. and Zhang, Junxi
- Abstract
Abstract.: This paper studies the equilibrium dynamics and indeterminacy of equilibria in an endogenous growth model with endogenous fertility choice. We characterize the conditions that give rise to an unique equilibrium as well as multiple equilibria. Whenever there exists a unique equilibrium, it will be globally determinate; when multiple equilibria arise, indeterminacy occurs. In particular, we find that two equilibria occur – one is associated with high fertility and low growth, while the other is associated with low fertility and high growth. A parameterized example is given to assess the empirical feasibility of our results. The validity of the neo-Malthusian relation between fertility and growth is then re-examined. Finally, we study the relation between growth and welfare and compare different balanced growth equilibria in terms of their lifetime-attained utility. JEL classifications: O41, J13
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- 1997
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39. Liquidity, Transaction Costs, and Real Activity
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Zhang, Junxi
- Abstract
This paper studies the liquidity effect in a pecuniary transaction‐cost model. To model the asymmetric impact of monetary injections, we consider two behavioral assumptions: sluggish money demand and sluggish firm investment. It is found that, under reasonable parameterization, the model is capable of generating a dominant liquidity effect. Our result suggests that, with alternative monetary specifications and behavioral assumptions, general equilibrium models are still useful for studying the liquidity effect at business cycle frequencies.
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- 1998
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40. Negative differential capacitance in InGaAs/InAlAs photodetector
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Guina, Mircea, Gong, Haimei, Lu, Jin, Liu, Dong, Zhang, Junxi, and Chen, Jun
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- 2018
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41. Effect of ambient temperature on the dry sliding wear of Vanadis 4 Extra steel
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Zhang, Junxi, Yi, Xiangbin, Liu, Limei, and Shen, Jiancheng
- Abstract
A pin-on-disk friction and wear test was conducted to test the critical load for serious dry sliding wear of Vanadis 4 Extra steel at a sliding speed of 0.691 m/s, at room temperature, 200 degC and 400 degC respectively. Using scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS), the wear surface morphologies, wear mechanism and reasons were analysed. Results show that: with increasing temperature, the critical load for serious wear of Vanadis 4 Extra steel first increased and then decreased. The critical loads leading to serious wear were 900 N and 800 N at room temperature and 400 degC, respectively, while, there was no serious wear at 200 degC at less than 1000 N. There were abrasive particles found under different loads: as the load and temperature increased, the formation of oxide films on the worn surface plays an decisive role in wear: when applying a load smaller than the critical load, oxide films can protect and lubricate the steel substrate, presenting slight oxidative wear; when applying a load greater than the critical load, oxide films on the worn surface were ruptured and spalled, with mainly oxidative delamination wear being observed.
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- 2018
42. Influence of Direct Current Electric Field on Electrode Process of Carbon Steel under Thin Electrolyte Layers
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Chen, Yang, Yang, Yan, Zhang, Junxi, Zhang, Xin, Dai, Nianwei, and Zhang, Lai-Chang
- Abstract
Although the corrosion behavior of metals under thin electrolyte layers (TELs) has been widely studied, little is understood about the electrode processes under these layers and even less so when exposed to a direct current (DC) electric field. This work shows that the open circuit potential (OCP) shifts negatively, the current density of oxygen reduction increases and initial hydrogen evolution potential shifts positively with enhancing the DC electric field intensity. The OCP shifts positively under the polarity reversal of DC electric field. The area covered with corrosion product decreases with increasing DC electric filed intensity. All these results indicate that the applied DC electric filed promotes the corrosion resistance of carbon steel. The synergistic effect of electric field on the electrode process of TELs has also been discussed in depth.
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- 2018
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43. Heat Treatment Degrading the Corrosion Resistance of Selective Laser Melted Ti-6Al-4V Alloy
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Dai, Nianwei, Zhang, Junxi, Chen, Yang, and Zhang, Lai-Chang
- Abstract
Ti-6Al-4V alloy produced by selective laser melting (SLM) was reported to exhibit an inferior corrosion resistance compared with the traditionally processed Grade 5 alloy, due to the formation of high-energy metastable α′martensite with regard to α martensite. This work manipulates the transformation of α′martensite to α martensite by heat-treatment in SLM-produced Ti-6Al-4V alloy and studies the effect on its corrosion behavior using electrochemical tests and microstructural analysis. The electrochemical results reveal that the heat-treated SLM-produced samples exhibit a higher corrosion rate than the as-received counterparts. The microstructural characterization results show that the acicular α′martensite vanishes gradually, and a plate-shaped α phase and a lamellar α + β mixture continuously form with enhancing heat-treatment temperature, which increases the grain size. The relation between changes in grain size and corrosion resistance of SLM-produced Ti-6Al-4V has been discussed in detail.
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- 2017
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44. High-sensitivity refractive index sensor based on large-angle tilted fiber grating with carbon nanotube deposition
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Berghmans, Francis, Mignani, Anna G., Badmos, Abdulyezir A., Sun, Qizhen, Yan, Zhijun, Arif, Raz N., Zhang, Junxi, Rozhin, Alex, and Zhang, Lin
- Published
- 2016
- Full Text
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