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15篇 您的检索式:作者名="CHEN Junxu"
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1Two Comparable Earthquakes Produced Greatly Different Coseismic Landslides:The 2015 Gorkha,Nepal and 2008 Wenchuan,China Events显示文摘The 2015 Gorkha Earthquake in Nepal and the 2008 Wenchuan Earthquake in China occurred at the south and southeast margins of the Tibetan Plateau, respectively. Both earthquakes had similar magnitudes of Mw 7.8 and 7.9, caused catastrophic loss of life and damage to property, and generated tens of thousands of landslides. Comparisons of pre- and post-quake satellite images supported by field investigations show that the Gorkha Earthquake triggered at least 2 064 large landslides(defined as covering an area ≥10 000 m^2) over a ~35 600 km^2 region with a volume of(444–584)×10~6(average 509×10~6) m^3 and total area of 44.78×10~6 m^2. In contrast, the Wenchuan Earthquake triggered 25 580 large landslides over a region of ~44 000 km^2 with a volume of(7 128–9 479)×10~6(average 8 219×10~6) m^3 and a total area of about 670.65×10~6 m^2. Several controlling factors including topographic relief, slope steepness, and regional peak ground acceleration(PGA) were investigated to try to explain the great differences between the number, volume and area of the coseismic landslides associated with the two similar earthquakes. We found that the differences primarily arose from an unexpected factor, the dip angle of the seismogenic fault. This discovery should aid understanding the failure mechanisms of quake-triggered landslides, and suggests that more factors should be taken into consideration in estimating coseismic landslide volumes from earthquake magnitudes.Chong Xu Xiwei Xu Yingying Tian Lingling Shen Qi Yao Xueqiang Huang Junxue Ma Xi Chen Siyuan Ma 2016Journal of Earth Science2016,27,6:14
2Vulnerability of Water Resources and Its Spatial Heterogeneity in Haihe River Basin, China显示文摘To manage water resources effectively, a multiscale assessment of the vulnerability of water resources on the basis of political boundaries and watersheds is necessary. This study addressed issues on the vulnerability of water resources and provided a multiscale comparison of spatial heterogeneity under a climate change background. Using improved quantitative evaluation methods of vulnerability, the Theil index and the Shannon-Weaver index, we evaluated the vulnerability of water resources and its spatial heterogeneity in the Haihe River Basin in four scales, namely, second-class water resource regions(Class ⅡWRRs), third-class water resource regions(Class Ⅲ WRRs), Province-Class ⅡWRRs, and Province-Class Ⅲ WRRs. Results show that vulnerability enhances from the north to south in the different scales, and shows obvious spatial heterogeneity instead of moving toward convergence in multiscale assessment results. Among the Class Ⅱ WRRs, the Tuhai-Majia River is the most vulnerable area, and the vulnerability of the Luanhe River is lower than that of the north of the Haihe River Basin, which in turn is lower than that of the south of the Haihe River Basin. In the scales of Class Ⅲ WRRs and Province-Class Ⅲ WRRs, the vulnerability shows obvious spatial heterogeneity and diversity measured by the Theil index and the Shannon-Weaver index. Multiscale vulnerability assessment results based on political boundaries and the watersheds of the Haihe River Basin innovatively provided in this paper are important and useful to characterize the real spatial pattern of the vulnerability of water resources and improve water resource management.XIA Jun CHEN Junxu WENG Jianwu YU Lei QI Junyu LIAO Qiang 2014Chinese Geographical Science2014,24,5:9
3Identification of Porphyra lines using computerized DNA fingerprinting显示文摘RAPD (Randomly Amplified Polymorphic DNA) analysis was performed with filaments of 15 Porphyra lines representing four important groups (P. yezoensis, P. haitanensis, P. katadai var. Hemiphylla and P. digospermatangia). Eight stable and repeatable RAPD bands amplified with two primers, OPN-02 and OPJ-18, were selected for the construction of DNA fingerprinting. The RAPD results were scored based on the presence or absence of each of the 8 bands and then converted to computer language expressed with two digitals, 1 and 0, which represented the presence (numbered as 1) or absence (numbered as 0) of each band, respectively. Based on these results, a model DNA fingerprint and a computerized DNA fingerprint were constructed. In the constructed DNA fingerprint, each Porphyra line has its unique fingerprinting pattern and can be easily distinguished from each other. Later, a software, named as PhGI, was designed based on this DNA fingerprinting. It can be used in practical Porphyra line identification.WangBin, Jia Jianhang, Shi Jinfeng, Chen Yihua, JinDemin, Xu Pu, Mei Junxue, Weng Manli 1. Institute of Genetics, Chinese Academy of Sciences, Beijing 100101 (E-mail: mlweng@genetics. ac. cn), China 2. Jiangsu Marine Fishery Institute, Nan 2001Acta Oceanologica Sinica2001,20,3:7
4Multi-object approach and its appfication to adaptive water management under climate change显示文摘This paper addresses issues on adaptive water management under the impact of climate change.Based on a set of comprehensive indicators of water system,a decision making approach of multi-objects is developed and applied to quantify water adaptive management for the demands of water sustainable use,water environmental protection and eco-water requirement under the climate change.For this study in China,two key indicators are proposed,namely(1) the water resources vulnerability(V) that was represented by integrated sensitivity(S) and resilience(C) of climate change impact on water resources,and(2) the sustainability of socio-economy and water environment,marked by DD,that is integrated scaler of socio-economic development(EG) based on the amount of GDP and the water environment and relative eco-system quality(LI).To find a reasonable solution for adaptive water management,a multi-objective decision making model of adaptive water management is further developed and the multi-objective model was transformed into an integrated single optimization model through developing an integrated measure function,called as VDD=DD/V.This approach has been applied to adaptive water resources planning and management for case study of China with new policy,called as the strict management of water resources based on three red line controls,i.e.,the control of total water use by the total water resources allocation,the control of lower water use efficiency by the water demand management and the control of the total waste water load by water quality management in the Eastern China Monsoon Region that covers major eight big river basins including Yangtze River,Yellow River,Haihe River and Huaihe River.It is shown that the synthetic representation of water resource vulnerability and socio-economic sustainability by the integrated objective function(VDD) and integrated decision making model are workable and practicable.Adaptive management effect of the criterion compliance rate and water use efficiency are more appreciable through new water policy of the three red line controls,which can reduce 21.3% of the water resources vulnerability(V) and increase 18.4% of the sustainability of socioeconomy and water environment(DD) for the unfavorable scenario of climate change in 2030.HONG Si XIA Jun CHEN Junxu WAN Long NING Like SHI Wei 2017Journal of Geographical Sciences2017,27,3:5
5Encapsulating a Ni(Ⅱ) molecular catalyst in photoactive metal–organic framework for highly efficient photoreduction of CO2显示文摘Photocatalytic reduction of CO2 to CO is a promising strategy for reducing atmospheric CO2 levels and storing solar radiation as chemical energy.Here,we demonstrate that a molecular catalyst[NiⅡ(bpet)(H2O)2]successfully encapsulated into a highly robust and visible-light responsive metal–organic framework(Ru-UiO-67)to fabricate composite catalysts for photocatalytic CO2 reduction.The composite Ni@Ru-UiO-67 photocatalysts show efficient visible-light-driven CO2 reduction to CO with a TON of 581 and a selectivity of 99% after 20-h illumination,because of the facile electron transfer from Ru-photosensitizer to Ni(Ⅱ)active sites in Ni@Ru-UiO-67 system.The mechanistic insights into photoreduction of CO2 have been studied based on thermodynamical,electrochemical,and spectroscopic investigation,together with density functional theory(DFT)calculations.This work shows that encapsulating molecular catalyst into photoactive MOF highlights opportunities for designing efficient,stable and recyclable photocatalysts.Zhi-Hao Yan Bo Ma Shu-Rong Li Junxue Liu Rong Chen Ming-Hao Du Shengye Jin Gui-Lin Zhuang La-Sheng Long Xiang-Jian Kong Lan-Sun Zheng 2019Science Bulletin2019,64,14:5
6Sensitivity and vulnerability of water resources in the arid Shiyang River Basin of Northwest China显示文摘The sensitivity and vulnerability of water resources to climate change is difficult to assess. In this study, we used a conceptual hydrologic model to investigate the sensitivity of streamflow to climate change. We also proposed a framework to evaluate the vulnerability of water resources in arid regions. We applied this framework to a case study of the Shiyang River Basin in Northwest China. Results showed that the precipitation and streamflow in Shiyang River Basin exhibited no significant trends of change from 1956 to 2010. In the past five decades, however, the temperature increased significantly by 0.37°C per decade. According to the sensitivity assessment, a 10% increase in precipitation and a 1°C increase in temperature altered mean annual streamflow by averages of 14.6% and –0.5%, respectively, from 1988 to 2005. In the 2000s, the calculated vulnerability of water resources in Shiyang River Basin was more than 0.95, indicating severe vulnerability. The increase in the amount of precipitation and the implementation of water-saving measures can reduce the vulnerability of water resources in the future; if precipitation increases by 10% per decade and the use of irrigation water decreases by 15% in the 2030s, the evaluated value of water resources vulnerability will be reduced to 0.79. However, the region remains highly vulnerable. The proposed framework for vulnerability assessment can be applied to the arid regions in Northwest China, and the results of our efforts can identify adaptation strategies and improve the management of water resources in such regions.Long WAN Jun XIA HongMei BU Si HONG JunXu CHEN LiKe NING 2014Journal of Arid Land2014,6,6:4
7A new concept - fotmation of permeating layers from nonactive antiwear additive显示文摘Dong Junxue Chen Guoxu 1994Lubr Eag1994,50,1:1
8Growth and fabrication of AlGaN/GaN HEMT based on Si(1<ce:hsp sp='0.16'/>1<ce:hsp sp='0.16'/>1) substrates by MOCVD显示文摘Weijun Luo Xiaoliang Wang Hongling Xiao Cuimei Wang Junxue Ran Lunchun Guo Jianping Li Hongxin Liu Yanling Chen Fuhua Yang Jinmin Li 2008Microelectronics Journal2008,,9:1
9Surface plasmon resonance hydrogen sensor based on metallic grat- ing with high sensitivity显示文摘LIN Kaiqun LU Yanghua CHEN Junxue 2008Optical Express2008,16,18:1
10Assessing canopy nitrogen and carbon content in maize by canopy spectral reflectance and uninformative variable elimination显示文摘Assessing canopy nitrogen content(CNC) and canopy carbon content(CCC) of maize by hyperspectral remote sensing data permits estimating cropland productivity, protecting farmland ecology, and investigating the nitrogen and carbon cycles in the atmosphere. This study aimed to assess maize CNC and CCC using canopy hyperspectral information and uninformative variable elimination(UVE). Vegetation indices(VIs) and wavelet functions were adopted for estimating CNC and CCC under varying water and nitrogen regimes. Linear, nonlinear, and partial least squares(PLS) regression models were fitted to VIs and wavelet functions to estimate CNC and CCC, and were evaluated for their prediction accuracy.UVE was used to eliminate uninformative variables, improve the prediction accuracy of the models, and simplify the PLS regression models(UVE-PLS). For estimating CNC and CCC, the normalized difference vegetation index(NDVI, based on red edge and NIR wavebands) yielded the highest correlation coefficients(r > 0.88). PLS regression models showed the lowest root mean square error(RMSE) among all models. However, PLS regression models required nine VIs and four wavelet functions, increasing their complexity. UVE was used to retain valid spectral parameters and optimize the PLS regression models.UVE-PLS regression models improved validation accuracy and resulted in more accurate CNC and CCC than the PLS regression models. Thus, canopy spectral reflectance integrated with UVE-PLS can accurately reflect maize leaf nitrogen and carbon status.Zhonglin Wang Junxu Chen Jiawei Zhang Xianming Tan Muhammad Ali Raza Jun Ma Yan Zhu Feng Yang Wenyu Yang 2022The Crop Journal2022,10,5:1
11Panax notoginseng and its components decreased hypertension via stimulation of endothelial-dependent vessel dilatation显示文摘Chunshui Pan Yingqing Huo Xiaojin An Gurbakhshish Singh Meng Chen Zhaoxiang Yang Junxue Pu Jian Li 20112011 (3-4)2011,,3:1
12Spatio-temporal variation and statistical characteristic of extreme dry spell in Yellow River Basin, China显示文摘Dunxian She Jun Xia Jiyun Song Hong Du Junxu Chen Long Wan 2013Theoretical and Applied Climatology2013,,1:1
13Breast-conserving surgery and combined therapy for women breast cancer: a report of 216 cases显示文摘Objective: To explore the therapeutic effect and associated techniques of breast-conserving therapy on patients with clinical stage I and stage II breast cancer. Methods: 216 female patients with breast cancer underwent breast-conserv- ing therapy from December 1993 to October 2004. Their data were analyzed retrospectively. The breast-conserving therapy consisted of lumpectomy or quadrant removal of the breast, postoperative radiotherapy, chemotherapy and endocrine ther- apy. Of them, 209 patients underwent axillary lymph node dissection. Results: There were no operative complications. 216 patients were followed-up 3 to 147 months, the medial follow-up time was 78 months. The local recurrence rate was 1.85%. Two patients died and one of them was not related with breast cancer. Presence or absence of fibrosis, shape of breast, asymmetry, pigmentation and handle were taken into consideration for cosmetic evaluation by the patients and experienced breast surgeon. Breasts were scored cosmetically as excellent and good in 199 patients, the rate of satisfactory was 92.13%. Conclusion: Breast-conserving therapy for early breast cancer is a safe and effective therapy. It has less trauma and less complications and can also raise the quality of life in the patients. But we must obey the strict indications and reasonable techniques.Xianju Qin Junxue Chen Hongwei Zhang Dafang Zhao Hua Zhang Wenjie Luo Qian Huang Shixian Lian Hanxing Tong 2007The Chinese-German Journal of Clinical Oncology2007,6,3:0
14Selective Adsorption of Ag(I) from Electronic Waste Leachate Using Modified Silk Sericin显示文摘A novel biosorbent was synthesized by grafting bisthiourea(BTU)on a silk sericin(SS)matrix.This biosorbent was denoted as BTU-SS and characterized by Fourier transform infrared spectroscopy(FTIR),zeta potential measurements,elemental analysis,and X-ray photoelectron spectroscopy(XPS).As revealed by the adsorption experiments,both BTU-SS and SS showed low affinity towards coexisting base metallic ions in Ag(I)-Cu(II)-Zn(II)-Ni(II)-Pb(II)electronic waste leachate mixtures,while their adsorption capacities towards Ag(I)reached 30.5 and 10.4 mg∙g-1 at a pH of 5.0,respectively.BTU-SS showed higher selectivity towards Ag(I)than SS,as revealed by the Ag(I)partition coefficients between the biosorbents and the leachate(16634.6 and 403.3,respectively).As further demonstrated by column experiments,BTU-SS allowed the separation of Ag(I)from an electronic waste leachate.Thermodynamic studies showed that the adsorption of Ag(I)was exothermic and spontaneous,while adsorption kinetic experiments revealed that chemisorption dominated the adsorption process with activation energies of 47.67 and 53.27 kJ∙mol-1 for BTU-SS and SS,respectively.FTIR and XPS analyses of fresh and Ag(I)-loaded BTU-SS further revealed an adsorption mechanism mainly involving electrostatic and coordination interactions.Sijing Zhang Fengjiao Ao Yongping Wang Junxue Zhao Yongliang Ji Shuangli Chen 2018Journal of Renewable Materials2018,6,1:0
15The azimuthal currents in the ion-driven magnetic nozzle显示文摘Ion-driven magnetic nozzles(Ti>Te)are designed as intrinsic parts of cutting-edge propulsive technologies such as variable specific impulse magnetoplasma rockets(VASIMRs)and applied-field magnetoplasmadynamic thrusters.Employing a two-dimensional axisymmetric particle-in-cell(PIC)code,in the ion-driven magnetic nozzle,the compositions and distributions of azimuthal currents in different axial regions are investigated under various inlet ion temperatures Ti0 and found to differ dramatically from that in the electron-driven magnetic nozzles.Previously reported to be all paramagnetic and vanishing under a high magnetic field,the azimuthal currents resulting from the E 3 B drift are shown to turn diamagnetic and sustain a considerable magnitude when Ti0 is considered.The previously reported profile of diamagnetic drift current is altered by the introduction of inlet ion temperature,and the paramagnetic part is significantly suppressed.Moreover,a wide range of paramagnetic currents appear downstream due to the inward detachment of ions,which can also be reduced by increasing inlet ion temperature.Albeit considered in this paper,the azimuthal currents resulting from grad-B and curvature drift are still negligible in all cases of interest.The magnitude of diamagnetic azimuthal currents increases with amplifying Ti0,indicating a clear physical image of energy transformation from ion thermal energy to the directed kinetic energy through electromagnetic processes in the magnetic nozzle.Additionally,the magnetic inductive strength also has noticeable impacts on the azimuthal currents,the current magnitude tends to decrease as the magnetic field increases,and over-increment of it may result in larger divergence angles and lower nozzle efficiency.Zhiyuan Chen Yibai Wang Haibin Tang Junxue Ren Min Li Peng Wu Jinbin Cao 2022Propulsion and Power Research2022,11,4:0
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