维普中文期刊产品整合服务
7篇 您的检索式:作者名="Xiangjun Zhen"
    题名 作者 年代 出处 被引量
1Cobalt and nitrogen codoped porous carbon as superior bifunctional electrocatalyst for oxygen reduction and hydrogen evolution reaction in alkaline medium显示文摘Cobalt and nitrogen codoped carbon materials(Co-N-C) were fabricated by pyrolysis of the mixture of poly(4-vinylpyridine) and cobalt chloride using SiO_2 nanoparticles as hard template, which were the first transition metal/nitrogen-codoped carbon bifunctional electrocatalyst derived from noncarbonizable polymer for ORR and HER. The as-made Co-N-C possessed hierarchical pore structure and high specific surface area, achieving excellent electrocatalytic performances for ORR and HER. Its ORR catalytic performances were comparable to those of Pt/C catalyst and its HER catalytic performances were superior to those of most doped carbon catalysts in KOH electrolyte. Moreover, its bifunctional electrocatalytic performances for ORR and HER were better than those of most bifunctional doped carbon catalysts in alkaline electrolyte.Xiaoxia Chen Xiangjun Zhen Hongyu Gong Le Li Jianwei Xiao Zhi Xu Deyue Yan Guyu Xiao Ruizhi Yang 2019Chinese Chemical Letters2019,30,3:2
2Accounting for CO2 Variability over East Asia with a Regional Joint Inversion System and Its Preliminary Evaluation显示文摘A regional surface carbon dioxide(CO_2) flux inversion system, the Tan-Tracker-Region, was developed by incorporating an assimilation scheme into the Community Multiscale Air Quality(CMAQ) regional chemical transport model to resolve fine-scale CO_2 variability over East Asia. The proper orthogonal decomposition-based ensemble four-dimensional variational data assimilation approach(POD-4 DVar) is the core algorithm for the joint assimilation framework, and simultaneous assimilations of CO_2 concentrations and surface CO_2 fluxes are applied to help reduce the uncertainty in initial CO_2 concentrations. A persistence dynamical model was developed to describe the evolution of the surface CO_2 fluxes and help avoid the 'signal-to-noise' problem; thus, CO_2 fluxes could be estimated as a whole at the model grid scale, with better use of observation information. The performance of the regional inversion system was evaluated through a group of single-observation-based observing system simulation experiments(OSSEs). The results of the experiments suggest that a reliable performance of Tan-Tracker-Region is dependent on certain assimilation parameter choices, for example, an optimized window length of approximately 3 h, an ensemble size of approximately 100, and a covariance localization radius of approximately 320 km. This is probably due to the strong diurnal variation and spatial heterogeneity in the fine-scale CMAQ simulation, which could affect the performance of the regional inversion system. In addition, because all observations can be artificially obtained in OSSEs, the performance of Tan-Tracker-Region was further evaluated through different densities of the artificial observation network in different CO_2 flux situations. The results indicate that more observation sites would be useful to systematically improve the estimation of CO_2 concentration and flux in large areas over the model domain. The work presented here forms a foundation for future research in which a thorough estimation of CO_2 flux variability over East Asia could be performed with the regional inversion system.xingxia kou xiangjun tian meigen zhang zhen peng xiaoling zhang 2017Journal of Meteorological Research2017,31,5:2
3Circulating exosome-like vesicles of humans with nondiabetic obesity impaired isletβ-cell proliferation,which was associated with decreased Omentin-1 protein cargo显示文摘The regulation ofβ-cell mass in the status of nondiabetic obesity remains not well understood.We aimed to investigate the role of circulating exosome-like vesicles(ELVs)isolated from humans with simple obesity in the regulation of isletβ-cell mass.Between June 2017 and July 2019,81 subjects with simple obesity and 102 healthy volunteers with normal weight were recruited.ELVs were isolated by ultra-centrifugation.The proliferations ofβ-cells and islets were measured by 5-ethynl-2′-deoxyuridine(EdU).Protein components in ELVs were identified by Quantitative Proteomic Analysis and verified by Western blot and ELISA.The role of specific exosomal protein was analyzed by gain-of-function approach in ELVs released by 3T3-L1 preadipocytes.Circulating ELVs from subjects with simple obesity inhibitedβ-cell proliferation in vitro without affecting its apoptosis,secretion,and inflammation.The protein levels of Rictor and Omentin-1 were downregulated in circulating ELVs from subjects with simple obesity and associated with the obesity-linked pathologic conditions.The ELV-carried Omentin-1 and Omentin-1 protein per se were validated to increaseβ-cell proliferation and activate Akt signaling pathway.Moreover,Omentin-1 in ELVs was downregulated by insulin.The circulating ELVs may act as a negative regulator forβ-cell mass in nondiabetic obesity through inhibitingβ-cell proliferation.This effect was associated with downregulated Omentin-1 protein in ELVs.This newly identified ELV-carried protein could be a mediator linking insulin resistance to impairedβ-cell proliferation and a new potential target for increasingβ-cell mass in obesity and T2DM.Qian Ge Xinxin Xie Xiangjun Chen Rongfeng Huang Cheng-Xue Rui Qianna Zhen Renzhi Hu Min Wu Xiaoqiu Xiao Xi Li 2022Genes & Diseases2022,9,4:1
4Efficacy of phytogenic extracts on growth performance and health of tilapia (Oreochromis niloticus × O. aureus)显示文摘The present study was conducted to evaluate the efficacy of phytogenic extract on growth and health of tilapia.Three experimental diets were designed as the basal diet(Con)and phytogenic extract(Flourishing,F)supplemented diets at 0.5 and 1 g/kg inclusion(F-1 and F-2),which the phytogenic additive was extracted from Eucommia ulmoides,Astragalus membranaceus,Lonicera japonica and Codonopsis pilosula.The three diets were fed to juvenile tilapia(14.0±0.1 g)with 30 fish per cage,and three replicate cages from the three groups were placed in one indoor concrete pool(a total of three pools were used).After 8 weeks of feeding,the weight gain was significantly increased,and feed conversion ratio was decreased in F-2 group(P<0.05)when compared to the control.Both levels of phytogenic extract significantly promoted the retentions of protein and lipid and the apparent digestibility coefficient of dry matter and protein(P<0.05).The activity of superoxide dismutase and the levels of white blood cells,haemoglobin and glutamic pyruvic transaminase were also significantly increased by the supplementation of phytogenic extract(P<0.05).The villus height in anterior intestine was significantly enhanced in F-1 and F-2 groups(P<0.05).After challenging with Aeromonas hydrophila,the cumulative mortality was significantly declined in F-1 and F-2 groups(P<0.05).In summary,the dietary supplementation of phytogenic extract at 1 g/kg feed could provide positive efficiency on growth,nutrient utilization,immunity,gut morphology and disease resistance of tilapia under the present conditions.Lumpan Poolsawat Yifeng Yu Xiaoqin Li Xu Zhen Wenxiang Yao Pu Wang Congyan Luo Xiangjun Leng 2022Aquaculture and Fisheries2022,7,4:0
5Effects of three positively buoyant dietary supplements on the buoyancy of feces,growth and intestinal health of Tilapia,Oreochromis niloticusO.aureus显示文摘Two trials were conducted to evaluate the effects of positively buoyant dietary materials on growth,intestinal health,and fecal properties of tilapia.In trial 1,ten diets containing 0(control)1%,2%or 3%cork,expanded and vitrified microball or expanded vermiculilite fine particles(250e450 mm)were fed to tilapia fry(5.0±0.1 g)for 30 days to evaluate the effects on the growth and feeding efficiencies.In trial 2,the three buoyant materials with coarse particles(450e830 mm)were included in diets at 0(control),3%,4%or 5%supplementation levels to feed tilapia juveniles(55.0±1.0 g),and the growth,feed efficiencies,evacuation velocity,fecal floatability and intestinal histology were examined after 21 days feeding.In trial 1,the weight gain(WG)of the fish significantly decreased with the supplementation of 2%,3%cork,3%microball or 3%vermiculite(P<0.05),and the feed conversion ratio(FCR)was significantly increased by 3%cork and 3%vermiculite(P<0.05)when compared to the control.In trial 2,cork-fed groups were observed to have more floating feces than microball-and vermiculite-fed groups.Dietary cork significantly decreased the sinking velocity of diets and feces(P<.05),but microball only decreased the sinking velocity of diets,and vermiculite(4%,5%)decreased the sinking velocity of feces(P<0.05).All buoyant materials supplemented groups showed lower WG and higher FCR than the control(P<.05).The intestine evacuation velocity and villus height,crypt depth,muscle thickness of intestinal walls were decreased by the increasing buoyant materials in diets,and 5%microball group showed the lowest values among all groups.In conclusion,dietary cork,microball and vermiculite(3%e5%)negatively affect the growth performance and intestinal histology of tilapia,and diets with cork supplementation could decrease the density of feed and feces to produce floating feces.Hang Yang Xiaoqin Li Dianyuan Huan Zhen Xu Yi Zhang Xiangjun Leng 2018Aquaculture and Fisheries2018,3,2:0
6Profiling the responsiveness of focal adhesions of human cardiomyocytes to extracellular dynamic nano-topography显示文摘Focal adhesion complexes function as the mediators of cell-extracellular matrix interactions to sense and transmit the extracellular signals.Previous studies have demonstrated that cardiomyocyte focal adhesions can be modulated by surface topographic features.However,the response of focal adhesions to dynamic surface topographic changes remains underexplored.To study this dynamic responsiveness of focal adhesions,we utilized a shape memory polymer-based substrate that can produce a flat-to-wrinkle surface transition triggered by an increase of temperature.Using this dynamic culture system,we analyzed three proteins(paxillin,vinculin and zyxin)from different layers of the focal adhesion complex in response to dynamic extracellular topographic change.Hence,we quantified the dynamic profile of cardiomyocyte focal adhesion in a time-dependent manner,which provides new understanding of dynamic cardiac mechanobiology.Huaiyu Shi Xiangjun Wu Shiyang Sun Chenyan Wang Zacharias Vangelatos Ariel Ash-Shakoor Costas P.Grigoropoulos Patrick T.Mather James H.Henderson Zhen Ma 2022Bioactive Materials2022,7,4:0
7Examining the Spatiotemporal Dynamics and Determinants of Land Urbanization in Prefecture-level Cities,China显示文摘Examining the spatiotemporal dynamics and determinants of land urbanization is critical for promoting healthy urban development and the rational use of land resources.Based on the dataset consisting of land use change data and selected factors in 2010 and2020,this study used visual analysis to reveal the spatiotemporal dynamics of land urbanization across prefecture-level cities in China.Meanwhile,the driving forces underlying land urbanization were examined by using geographical detector technique.Following are the findings:1)we find that there exist notable spatial variances in land urbanization across prefecture-level cities.Currently,the differentiation in land urbanization between the northern and southern cities is more pronounced than that between the coastal and inland cities,or between the eastern and western cities.Prefecture-level cities located in central and western China have experienced the most rapid growth in land urbanization.Conversely,the growth rate in northeastern China is the lowest,while the velocity in eastern China remains relatively stable.By using spatial autocorrelation analysis,this study reveals that the land urbanization level in prefecture-level cities has significant spatial agglomeration.2)We further find that land urbanization in China is influenced by factors related to urban land supply and demand,and urban population growth,economic growth,land financial and political incentive have greater impact on land urbanization than other factors.3)We also find that the impacts of determinants on China’s land urbanization vary over time,the explanatory power of economic development increased,while the explanatory power of state forces declined.We argue that integrating the supply and demand factors of land urbanization can provide a more comprehensive understanding of the driving mechanisms underlying land urbanization in China and other transitional countries,and help decision-makers in these countries formulate more detailed and specific land urbanization policies.YANG Zhen ZHU Huxiao ZHANG Xinlin OU Xiangjun 2024Chinese Geographical Science2024,34,1:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费