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1Preliminary Results of In-situ Stress Measurements along the Longmenshan Fault Zone after the Wenchuan M_s 8.0 Earthquake显示文摘Four months after the Wenchuan M_s 8 earthquake in western Sichuan,China,in situ stress measurements were carried out along the Longmenshan fault zone with the purpose of obtaining stress parameters for earthquake hazard assessment.In-situ stresses were measured in three new boreholes by using overcoring with the piezomagnetic stress gauges for shallow depths and hydraulic fracturing for lower depths.The maximum horizontal stress in shallow depths(~20 m) is about 4.3 MPa,oriented N19°E,in the epicenter area at Yingxiu Town,about 9.7 MPa,oriented N51°W,at Baoxing County in the southwestern Longmenshan range,and about 2.6 MPa,oriented N39°E,near Kangding in the southernmost zone of the Longmenshan range.Hydraulic fracturing at borehole depths from 100 to 400 m shows a tendency towards increasing stress with depth.A comparison with the results measured before the Wenchuan earthquake along the Longmenshan zone and in the Tibetan Plateau demonstrates that the stress level remains relatively high in the southwestern segment of the Longmenshan range,and is still moderate in the epicenter zone.These results provide a key appraisal for future assessment of earthquake hazards of the Longmenshan fault zone and the aftershock occurrences of the Wenchuan earthquake.WU Manlu ZHANG Yueqiao LIAO Chunting CHEN Qunce MA Yinsheng WU Jinsheng YAN Junfeng OU Mingyi 2009Acta Geologica Sinica(English Edition)2009,83,4:31
2Antigenic variation of the human influenza A(H3N2) virus during the 2014–2015 winter season显示文摘The human influenza A(H3N2) virus dominated the 2014–2015 winter season in many countries and caused massive morbidity and mortality because of its antigenic variation. So far, very little is known about the antigenic patterns of the recent H3N2 virus. By systematically mapping the antigenic relationships of H3N2 strains isolat ed since 2010, we discov ered that two groups with obvious antigenic divergence, named SW13(A/Switzerland/9715293/2013-like strains) and HK14(A/Hong Kong/5738/2014-like strains), co-circulated during the 2014–2015 winter season. HK14 group co-circulated with SW13 in Europe and the United States during this season, while there were few strains of HK14 in China's Mainland, where SW13 has dominated since 2012. Furthermore, we found that substitutions near the receptor-binding site on hemagglutinin played an important role in the antigenic variation of both the groups. These findings provide a comprehensive understanding of the recent antigenic evolution of H3N2 virus and will aid in the selection of vaccine strains.HUA Sha LI XiYan LIU Mi CHENG YanHui PENG YouSong HUANG WeiJuan TAN MinJu WEI HeJiang GUO JunFeng WANG DaYan WU AiPing SHU YueLong JIANG TaiJiao 2015Science China(Life Sciences)2015,58,9:17
3Cotton GhMYB7 is predominantly expressed in developing fibers and regulates secondary cell wall biosynthesis in transgenic Arabidopsis显示文摘The secondary cell wall in mature cotton fibers contains over 90%cellulose with low quantities of xylan and lignin.However,little is known regarding the regulation of secondary cell wall biosynthesis in cotton fibers.In this study,we characterized an R2R3-MYB transcription factor,Gh MYB7,in cotton.Gh MYB7 is expressed at a high level in developing fibers and encodes a MYB protein that is targeted to the cell nucleus and has transcriptional activation activity.Ectopic expression of Gh MYB7 in Arabidopsis resulted in small,curled,dark green leaves and also led to shorter inflorescence stems.A cross-sectional assay of basal stems revealed that cell wall thickness of vessels and interfascicular fibers was higher in transgenic lines overexpressing Gh MYB7 than in the wild type.Constitutive expression of Gh MYB7 in Arabidopsis activated the expression of a suite of secondary cell wall biosynthesis-related genes(including some secondary cell wall-associated transcription factors),leading to the ectopic deposition of cellulose and lignin.The ectopic deposition of secondary cell walls may have been initiated before the cessation of cell expansion.Moreover,Gh MYB7 was capable of binding to the promoter regions of At SND1 and At Ces A4,suggesting that Gh MYB7 may function upstream of NAC transcription factors.Collectively,these findings suggest that Gh MYB7 is a potential transcriptional activator,which may participate in regulating secondary cell wall biosynthesis of cotton fibers.Junfeng Huang Feng Chen Siyu Wu Juan Li Wenliang Xu 2016Science China(Life Sciences)2016,59,2:15
4Amplitude-Integrated Electroencephalography Predicts Outcome in Patients with Coma After Acute Brain Injury显示文摘Prognostication of coma patients after brain injury is important, yet challenging. In this study, we evaluated the predictive value of amplitude-integrated electroencephalography(a EEG) for neurological outcomes in coma patients. From January 2013 to January 2016, 128 coma patients after acute brain injury were prospectively enrolled and monitored with a EEG. The 6-month neurological outcome was evaluated using the Cerebral Performance Category Scale. a EEG monitoring commenced at a median of 7.5 days after coma onset. Continuous normal voltage predicted a good 6-month neurological outcome with a sensitivity of 93.6% and specificity of 85.2%. In contrast, continuous extremely low voltage, burst-suppression, or a flat tracing was correlated with poor 6-month neurological outcome with a sensitivity of 76.5% and specificity of 100%. In conclusion, a EEG is a promising predictor of 6-month neurological outcome for coma patients after acute brain injury.Wendong You Qilin Tang Xiang Wu Junfeng Feng Qing Mao Guoyi Gao Jiyao Jiang 2018Neuroscience Bulletin2018,34,4:15
5Friction and Wear Behavior of Resin/Graphite Composite under Dry Sliding显示文摘The friction and wear behavior of resin/graphite composite has been investigated using a pin-on-disc configuration under dry sliding condition. The results showed that the resin/graphite composite exhibited much better mechanical and tribological properties compared with the unimpregnated graphite. The friction coefficient was reduced by addition of furan resin, which could also prevent the'dusting' wear at loads more than 15 MPa. The steady and lubricated transfer film was easily formed on the counterpart surface due to the interaction of furan resin and wear debris of graphite, which was useful to reduce the wear rate of the resin/graphite composite. The composite is highly promising for mechanical sealing application and can be used at high load for long time sliding.Zhenguo Zhu Shuo Bai Junfeng Wu Li Xu Ting Li Yong Ren Chang Liu 2015Journal of Materials Science & Technology2015,31,3:14
6The earthquake-related disturbances in ionosphere and project of the first China seismo-electromagnetic satellite显示文摘Based on the case studies and statistical analysis of earthquake-related ionospheric disturbances mainly from DEMETER satellite,ground-based GPS and ionosounding data,this paper summarizes the statistical characteristics of earthquake-related ionospheric disturbances,including electromagnetic emissions,plasma perturbations and variation of energetic particle flux.According to the main results done by Chinese scientists, fusing with the existed study from global researches,seismo-ionospheric disturbances usually occurred a few days or hours before earthquake occurrence.Paralleling to these case studies,lithosphere-atmosphere-ionosphere (LAI) coupling mechanisms are checked and optimized.A thermo-electric model was proposed to explain the seismo-electromagnetic effects before earthquakes.A propagation model was put forward to explain the electromagnetic waves into the ionosphere.According to the requirement of earthquake prediction research,China seismo-electromagnetic satellite,the first space-based platform of Chinese earthquake stereoscopic observation system,is proposed and planned to launch at about the end of 2014.It focuses on checking the LAI model and distinguishing earthquake-related ionospheric disturbance.The preliminary design for the satellite will adopt CAST-2000 platform with eight payloads onboard.It is believed that the satellite will work together with the ground monitoring network to improve the capability to capture seismo-electromagnetic information,which is beneficial for earthquake monitoring and prediction researches.Xuhui Shen Xuemin Zhang Lanwei Wang Huaran Chen Yun Wu Shigeng Yuan Junfeng Shen Shufan Zhao Jiadong Qian Jianhai Ding 2011Earthquake Science2011,24,6:13
7The Exhumation History of North Qaidam Thrust Belt Constrained by Apatite Fission Track Thermochronology:Implication for the Evolution of the Tibetan Plateau显示文摘Determining the spatio-temporal distribution of the deformation tied to the India-Eurasian convergence and the impact of pre-existing weaknesses on the Cenozoic crustal deformation is significant for understanding how the convergence between India and Eurasia contributed to the development of the Tibetan Plateau. The exhumation history of the northeastern Tibetan Plateau was addressed in this research using a new apatite fission track(AFT) study in the North Qaidam thrust belt(NQTB). Three granite samples collected from the Qaidam Shan pluton in the north tied to the Qaidam Shan thrust, with AFT ages clustering in the Eocene to Miocene. The other thirteen samples obtained from the Luliang Shan and Yuka plutons in the south related to the Luliang Shan thrust and they have showed predominantly the Cretaceous AFT ages. Related thermal history modeling based on grain ages and track lengths indicates rapid cooling events during the Eocene-early Oligocene and since late Miocene within the Qaidam Shan, in contrast to those in the Cretaceous and since the Oligocene-Miocene in the Luliang Shan and Yuka region. The results, combined with published the Cretaceous thermochronological ages in the Qaidam Shan region, suggest that the NQTB had undergo rapid exhumation during the accretions along the southern Asian Andean-type margin prior to the India-Eurasian collision. The Cenozoic deformation initially took place in the North Qaidam thrust belt by the Eocene, which is consistent with the recent claim that the deformation of the northeastern Tibetan Plateau initiated in the Eocene as a response to continental collision between India and Eurasia. The immediate deformation responding to the collision is tentatively attributed to the pre-existing weaknesses of the lithosphere, and therefore the deformation of the northeastern Tibetan Plateau should be regarded as a boundary-condition-dependent process.CHENG Xiaogan LIN Xiubin WU Lei CHEN Hanlin XIAO Ancheng GONG Junfeng ZHANG Fengqi YANG Shufeng 2016Acta Geologica Sinica(English Edition)2016,90,3:10
8Metal-organic framework-derived, Zn-doped porous carbon polyhedra with enhanced activity as bifunctional catalysts for rechargeable zinc-air batteries显示文摘锌空气电池最近与他们的锂离子对应物相比由于更大的存储能力和更低的费用吸引了可观的兴趣。为氧减小反应(ORR ) 和氧进化反应(OER ) 的电极催化剂在可充电的锌空气电池的操作起一个关键作用。此处,我们报导简单、可伸缩的策略作为先锋用做 Zn 的共同基于的 zeolitic imidazolate 框架(ZnCo-ZIFs ) 制作多孔的碳 polyhedra。惊人地,做的 Zn 导致更小的公司 nanoparticles 和更高的氮内容,它接着提高获得的多孔的碳 polyhedra 的 ORR 和 OER 活动。做 N 的碳和钴 nanoparticles 在的 synergistic 效果合成,源于碳的高 graphitization 的改进传导性,和多孔的多面的结构的大表面区域在碱的媒介与优秀 ORR 和 OER electrocatalytic 活动导致了多孔的碳 polyhedra。更重要地,空气阴极在新窗户中在主要、可充电的锌空气 batteries.Open 图象基于最佳的多孔的碳 polyhedra 推进展出优异性能到 Pt/CXuan Wu Ge Meng Wenxian Liu Tian Li Qiu Yang Xiaoming Sun Junfeng Liu 2018Nano Research2018,11,1:10
9Acupuncture at the “Huatuojiaji” point affects nerve root regional interleukin-1 level in a rat model of lumbar nerve root compression显示文摘BACKGROUND:It has been shown that interleukin-1 (IL-1) may cause inflammatory reactions, which stimulate the nerve root of patients with lumbar intervertebral disc protrusion and leads to pain. Whether the clinical curative effects of acupuncture in the treatment of lumbar and leg pain are linked to an inhibition of local IL-1 secretion is unknown. OBJECTIVE: To assess the influence of acupuncture on IL-1, this study was designed to verify the effects of acupuncture at the 'Huatuojiaji (Extra)' point on the nerve root in a rat model of lumbar nerve root compression, compared with administration of meloxicam, a non-steroidal anti-inflammatory drug. DESIGN, TIME AND SETTING: Randomized, controlled, molecular biology experiment, performed at the Experimental Center, Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University between September 2005 and April 2006. MATERIALS: Forty healthy adult Sprague Dawley rats of either gender were included in this study. The rats were randomly and evenly divided into the following four groups: normal control, model, acupuncture and meloxicam groups. Lumbar nerve root compression was induced in rats in the model, acupuncture, and meloxicam groups by inserting a specially made silicon rubber slice at the juncture of the L5 nerve root and the dural sac. The acupuncture needle (pattern number N3030, 30#, 1.5 inch) was purchased from Suzhou Medical Appliance Factory, China. IL-1 enzyme linked immunosorbent assay (ELISA) kit was purchased from Santa Cruz Biotechnology, Inc., USA. METHODS: The acupuncture group was acupunctured at the 'Huatuojiaji' point, which is lateral to the compressed L5-6 nerve root, with an acupuncture depth of 0.5 cm. There were two treatment courses, each of involved seven 20-minute acupuncture sessions, one session a day. The meloxicam group was administered intragastrically 3.75 mg/kg meloxicam (5 mg meloxicam /10 mL physiological saline). Rats in the normal control group and model group received an intragastric administration of 10 mL/kg physiological saline. All administrations were performed once a day. MAIN OUTCOME MEASURES: At day 14 post-surgery, the IL-1 level in the compressed nerve root was determined by a streptavidin-peroxidase (S-P) immunohistochemical method, and IL-1β mRNA expression in the compressed nerve root was simultaneously detected by real-time reverse transcription-polymerase chain reaction. RESULTS: The expression levels of IL-1 and IL-1β mRNA in the L5 nerve root were significantly higher in the model group than in the control group (P < 0.01). However, the expression levels of IL-1 and IL-1β mRNA were significantly lower in the acupuncture and meloxicam groups than in the model group (P < 0.05–0.01). Expression levels of IL-1 and IL-1β mRNA were significantly higher in the acupuncture group than in the meloxicam group (P < 0.01). CONCLUSION: Acupuncture at the 'Huatuojiaji' point decreases the IL-1 level by inhibiting IL-1β mRNA expression to a greater extent than meloxicam administration.Yaochi Wu Junfeng Zhang Chongmiao Wang Yanyan Xie Jinghui Zhou 2008Neural Regeneration Research2008,3,8:7
10Effect of warm acupuncture on nitric oxide synthase and calcitonin gene-related peptide in a rat model of lumbar nerve root compression显示文摘BACKGROUND:Varying degrees of inflammatory responses occur during lumbar nerve root compression.Studies have shown that nitric oxide synthase(NOS) and calcitonin gene-related peptide(CGRP) are involved in secondary disc inflammation. OBJECTIVE:To observe the effects of warm acupuncture on the ultrastructure of inflammatory mediators in a rat model of lumbar nerve root compression,including NOS and CGRP contents. DESIGN,TIME AND SETTING:Randomized,controlled study,with molecular biological analysis, was performed at the Experimental Center,Sixth People's Hospital Affiliated to Shanghai Jiao Tong University,between September 2006 and April 2007. MATERIALS:Acupuncture needles and refined Moxa grains were purchased from Shanghai Taicheng Technology Development Co.,Ltd.,China;Mobic tablets were purchased from Shanghai Boehringer Ingelheim Pharmaceuticals Co.,Ltd.,China;enzyme linked immunosorbent assay (ELISA) kits for NOS and CGRP were purchased from ADL Biotechnology,Inc.,USA. METHODS:A total of 50,healthy,adult Sprague-Dawley rats,were randomly divided into five groups normal,model,warm acupuncture,acupuncture,and drug,with 10 rats in each group.Rats in the four groups,excluding the normal group,were used to establish models of lumbar nerve root compression.After 3 days,Jiaji points were set using reinforcing-reducing manipulation in the warm acupuncture group.Moxa grains were burned on each needle,with 2 grains each daily.The acupuncture group was the same as the warm acupuncture group,with the exception of non-moxibustion.Mobic suspension(3.75 mg/kg) was used in the oral drug group,once a day. Treatment of each group lasted for 14 consecutive days.Modeling and medication were not performed in the normal group. MAIN OUTCOME MEASURES:The ultrastructure of damaged nerve roots was observed with transmission electron microscopy;NOS and CGRP contents were measured using ELISA. RESULTS:The changes of the radicular ultramicrostructure were characterized by Wallerian degeneration;nerve fibers were clearly demyelinated;axons collapsed or degenerated;outer Schwann cell cytoplasm was swollen and its nucleus was compacted.Compared with the normal group,NOS and CGRP contents in the nerve root compression zone in the model group were significantly increased(P<0.01).Nerve root edema was improved in the drug,acupuncture and the warm acupuncture groups over the model group.NOS and CGRP expressions were also decreased with the warm acupuncture group having the lowest concentration(P<0.01). CONCLUSION:In comparison to the known effects of Mobic drug and acupuncture treatments,the warm acupuncture significantly decreased NOS and CGRP expression which helped improve the ultrastructure of the comoressed nerve root.Yaochi Wu Yiqun Mi Peng Zhang Junfeng Zhang Wei Chen 2009Neural Regeneration Research2009,4,6:5
11Removal of benzotriazole by heterogeneous photoelectro-Fenton like process using ZnFe_2O_4 nanoparticles as catalyst显示文摘ZnFe2O4 nanoparticles(ZFNPs) were developed as catalyst for the degradation of benzotriazole(BTA) by heterogeneous photoelectroFenton(PE-Fenton) like process.ZFNPs were prepared by a co-precipitation process and then characterized with transmission electron microscopy(TEM),X-ray fluorescence(XRF),X-ray diffraction(XRD) and BET surface area.Using such ZFNPs as catalyst,the degradation of BTA was investigated.Due to the high catalytic activity of ZFNPs,PE-Fenton like process showed efficient degradation of BTA.The influencing factors such as pH,dosage of ZFNPs,applied potential and initial concentration of BTA were systematically investigated.Under the optimum conditions,91.2% of BTA was removed after 180 min treatment.Junfeng Wu Wenhong Pu Changzhu Yang Man Zhang Jingdong Zhang 2013Journal of Environmental Sciences2013,25,4:5
12Telmisartan promotes proliferation and differentiation of endothelial progenitor cells via activation of Akt显示文摘Cao Zheng Yang Yong Hua Xianping Wu Ruixia Wang Junfeng Zhou Ming Zhan Zhongqun Chen Pingying 2014Chinese Medical Journal2014,,1:5
13Ecological risk assessment of Cd and other heavy metals in soil-rice system in the karst areas with high geochemical background of Guangxi,China显示文摘Karst areas are widely distributed in China,and the soil derived in these areas is enriched with trace elements and has the typical characteristics of high geochemical background.Therefore,soil ecological risk has gradually attracted extensive attention.In this study,1090 sets of rice grains and paired rhizosphere soils were collected as research objects from the outcropped karst areas of carbonate rocks in Guangxi,and the concentration characteristics and influencing factors of heavy metals,such as Cd and As,in rice grains and the corresponding soils were studied.According to the Chinese Soil Environmental Quality Standard(GB 15618-2018),the proportion of karstic soil samples in Guangxi with heavy metal(As,Cd,Cr,Cu,Hg,Ni,Pb and Zn)concentrations that exceed the standard risk screening values was generally greater than that of surface soils in China or non-karstic soils in Guangxi.Notably,Cd and As were the most prominently enriched heavy metals in soils.According to the Chinese Food Safety Standard(GB 2762-2017),Pb in rice grains from the studied area did not exceed the standard;the exceedance rates of Cr,Hg,and inorganic As were only about 1%;and the exceedance rate of Cd was 12.5%.Soil Cd concentration increased gradually whereas the concentration and exceedance rate of Cd in rice grains decreased gradually with the increase of soil pH.Specifically,the exceedance rate of Cd in rice grains was only 4%when soil pH>6.5.The results indicated that the risk screening values of Cd element in the Chinese Soil Environmental Quality Standard are not satisfactorily applicable to the ecological risk assessment of Cd in karstic soils.Therefore,the recommended threshold values for the safe utilization and risk control of Cd in karstic soils was proposed so as to provide a basis for soil environmental quality hierarchization,pollution risk control and land safety zoning of agricultural land in karst areas in China.Qiong YANG Zhongfang YANG Qizuan ZHANG Xu LIU Xiaoxiong ZHUO Tiansheng WU Lei WANG Xueji WEI Junfeng JI 2021Science China Earth Sciences2021,64,7:5
14A novel organic-inorganic hybrid monolith for trypsin immobilization显示文摘In proteomics, attention has focused on various immobilized enzyme reactors (IMERs) for the realization of high throughput digestion. In this report, a novel organic-inorganic hybrid monolith based IMER was prepared in a 100 μm i.d. capillary with 3-glycidoxypropyltrimethoxysilane (GLYMO) as the monomer and tetraethoxysilane (TEOS) as the crosslinker. Trypsin immobilization was achieved via the reaction between vicinal diol groups, which were obtained from hydrolysis of epoxy groups, and the amino groups of trypsin. Bovine serum albumin was digested thoroughly by this IMER in 47 s. After micro-reverse phase liquid chromatography-tandem mass spectrometry (μRPLC-MS/MS) analysis and database searching, beyond 35% sequence coverage was obtained, and the result was comparable to that of 12 h in solution digestion. The present IMER has potential for high throughput digestion.WU ShuaiBin MA JunFeng YANG KaiGuang LIU JinXiang LIANG Zhen ZHANG LiHua ZHANG YuKui 2011Science China(Life Sciences)2011,54,1:5
15Theoretical and simulation research of hydrodynamic instabilities in inertial-confinement fusion implosions显示文摘Inertial fusion energy(IFE)has been considered a promising,nearly inexhaustible source of sustainable carbon-free power for the world's energy future.It has long been recognized that the control of hydrodynamic instabilities is of critical importance for ignition and high-gain in the inertial-confinement fusion(ICF)hot-spot ignition scheme.In this mini-review,we summarize the progress of theoretical and simulation research of hydrodynamic instabilities in the ICF central hot-spot implosion in our group over the past decade.In order to obtain sufficient understanding of the growth of hydrodynamic instabilities in ICF,we first decompose the problem into different stages according to the implosion physics processes.The decomposed essential physics processes that are associated with ICF implosions,such as Rayleigh-Taylor instability(RTI),Richtmyer-Meshkov instability(RMI),Kelvin-Helmholtz instability(KHI),convergent geometry effects,as well as perturbation feed-through are reviewed.Analytical models in planar,cylindrical,and spherical geometries have been established to study different physical aspects,including density-gradient,interface-coupling,geometry,and convergent effects.The influence of ablation in the presence of preheating on the RTI has been extensively studied by numerical simulations.The KHI considering the ablation effect has been discussed in detail for the first time.A series of single-mode ablative RTI experiments has been performed on the Shenguang-Ⅱlaser facility.The theoretical and simulation research provides us the physical insights of linear and weakly nonlinear growths,and nonlinear evolutions of the hydrodynamic instabilities in ICF implosions,which has directly supported the research of ICF ignition target design.The ICF hot-spot ignition implosion design that uses several controlling features,based on our current understanding of hydrodynamic instabilities,to address shell implosion stability,has been briefly described,several of which are novel.LiFeng Wang WenHua Ye XianTu He JunFeng Wu ZhengFeng Fan Chuang Xue HongYu Guo WenYong Miao YongTeng Yuan JiaQin Dong Guo Jia Jing Zhang YingJun Li Jie Liu Min Wang YongKun Ding WeiYan Zhang 2017Science China(Physics,Mechanics & Astronomy)2017,60,5:4
16Application of a neural network system combined with genetic algorithm to rank coalbed methane reservoirs in the order of exploitation priority显示文摘A new method based on the combination of a neural network and a genetic algorithm was proposed to rank the order of exploitation priority of coalbed methane reservoirs.The neural network was used to acquire the weights of reservoir parameters through sample training and genetic algorithm was used to optimize the initial connection weights of nerve cells in case the neural network fell into a local minimum.Additionally,subordinate functions of each parameter were established to normalize the actual values of parameters of coalbed methane reservoirs in the range between zero and unity.Eventually, evaluation values of all coalbed methane reservoirs could be obtained by using the comprehensive evaluation method,which is the basis to rank the coalbed methane reservoirs in the order of exploitation priority.The greater the evaluation value,the higher the exploitation priority.The ranking method was verified in this paper by ten exploited coalbed methane reservoirs in China.The evaluation results are in agreement with the actual exploitation cases.The method can ensure the truthfulness and credibility of the weights of parameters and avoid the subjectivity caused by experts.Furthermore,the probability of falling into local minima is reduced,because genetic the algorithm is used to optimize the neural network system.Li Weichao Wu Xiaodong Shi Junfeng 2008Petroleum Science2008,5,4:4
17Structural parameter optimization for novel internal-loop iron–carbon micro-electrolysis reactors using computational fluid dynamics显示文摘It is generally recognized that internal-loop reactors are well-developed mass and heat-transfer multiphase flow reactors. However, the internal flow field in the internal-loop reactor is influenced by the structure parameter of the reactor, which has a great effect on the reaction efficiency. In this study, the computational fluid dynamics simulation method was used to determine the influence of reactor structure on flow field, and a volume-offluid model was employed to simulate the gas–liquid, two-phase flow of the internal-loop micro-electrolysis reactor. Hydrodynamic factors were optimized when the height-to-diameter ratio was 4:1, diameter ratio was9:1, draft-tube axial height was 90 mm. Three-dimensional simulations for the water distributor were carried out, and the results suggested that the optimal conditions are as follows: the number of water distribution pipes was four, and an inhomogeneous water distribution was used. According to the results of the simulation,the suitable structure can be used to achieve good fluid mechanical properties, such as the good liquid circulation velocity and gas holdup, which provides a good theoretical foundation for the application of the reactor.Lei Zhang Mengyu Wu Yanhe Han Meili Liu Junfeng Niu 2019Chinese Journal of Chemical Engineering2019,27,4:3
18Improved dispersion performance and interfacial compatibility of covalent-grafted MOFs in mixed-matrix membranes for gas separation显示文摘Mixed-matrix membranes(MMMs)have received much attention due to their processable advantages of polymer and high permeability and/or selectivity of porous metal-organic frameworks(MOFs)fillers.However,the interfacial defects caused by poor interaction between MOFs with polymers and the agglomeration phenomenon caused by uneven dispersion of MOFs are common problems in mixed-matrix membranes.Currently,the priming protocol is one of solutions to the above problems,but it cannot precisely regulate the dispersion of particles and the interfacial compatibility between two phases.Herein,covalent grafting of polyimide 6FDA-Durene onto the surface of UiO-66-NH2 can mitigate the aggregation of fillers inside the polymeric matrices and improve the interfacial interaction between two phases,thus significantly improving the CO_(2)/CH_(4)separation performance on the as-synthesized MMMs.The explored gas transport mechanism indicated that the improved separation was due to the raise of solubility selectivity.Furthermore,the stronger covalent bond between fillers and polyimide than physical interaction of priming protocol also endows the improved anti-plasticization phenomenon for CO_(2)/CH_(4)separation.Chongqing Wang Guangjie Ren Kaifeng Wei Donghui Liu Tingting Wu Jinlong Jiang Junfeng Qian Yichang Pan 2021Green Chemical Engineering2021,2,1:3
19Designing high-strength titanium alloy using pseudo-spinodal mechanism through diffusion multiple experiment and CALPHAD calculation显示文摘This study used the pseudo-spinodal mechanism to obtain the ultrafineαphase for designing highstrength titanium alloy.Diffusion multiple experiments were designed to find the composition range of TM-x Mo-y V alloy(TM:Ti-4.5 Al-2 Cr-2.5 Nb-2 Zr-1 Sn)for obtaining ultrafineαphase.CALPHAD results confirm that when the alloy composition is located near the intersection of theαandβphase free energy curves,the alloy will undergo pseudo-spinodal transformation and obtain the ultrafineαphase.The designed TM-6 Mo-3 V alloy has a yield strength of 1411 MPa and an elongation of 6.5%.The strength of the alloy depends on the thickness,fraction of theαphase and the solid solution strengthening effect of the alloying elements.The deformation mechanism of the alloy is the dislocation slip of theαandβphases and the twin deformation of theαphase.The large number ofα/βinterfaces produced by the fineαphase is the main reason for limiting the ductility of the alloy.The use of the pseudo-spinodal mechanism combined with diffusion multiple experiments and CALPHAD is an effective method for designing high-strength titanium alloys.Di Wu Libin Liu Lijun Zeng Wenguang Zhu Wanlin Wang Xiaoyong Zhang Junfeng Hou Baoliang Liu Jiafeng Lei Kechao Zhou 2021Journal of Materials Science & Technology2021,,15:3
20Characteristic analysis of ecosystem service value of water system in Taiyuan urban district based on LUCC显示文摘Changes in the land use and ecosystem service value of the 600 m buffer zone of Jinyang Lake and the 1000 m riparian zone of the Fenhe River in the Taiyuan urban district in China,were studied using satellite image data collected in June 2006 and June 2013.According to the ecosystem services assessment system based on expert knowledge,the ecosystem service value(ESV)per unit area was determined for various land-use types and the value of the water system and its buffer regions in the Taiyuan urban district were determined.And then the relationship between LUCC(Land Use/Cover Change)and ESV was discussed.Moreover,the accuracy and validity of the results was analyzed.The results showed that:(1)the areas of green vegetation and water bodies of Jinyang Lake and its buffer region decreased by 24.96%and 3.22%,respectively,between June 2006 and June 2013,whereas the areas of farmland and built-up land increased by 15.81%and 12.37%,respectively.At Jinyang Lake,the degree of dynamic change for green vegetation,water bodies,farmland,built-up land,and unused land was−0.13,−0.02,0.17,0.09,and−0.05,respectively.In the Fenhe River’s buffer region,the areas of green vegetation,farmland and unused land decreased by 1.36%,6.36%and 0.3%,respectively,but those of built-up land and water bodies increased by 1.41%and 6.61%,respectively.Their degree of dynamic change was−0.03,−0.02,−0.04,0.01 and 0.32,respectively;(2)In 2006,the landscape fragmentation indices(LFI)of Jinyang Lake buffer of 0-200 m zone were greater than 2,but those of 200-600 m buffer zone were less than 0.3,the water-body index not included.However,in 2013,the landscape fragmentation indices of green vegetation and water bodies of 0-600 m buffer zone were both high,meaning that the land-use pattern had improved.The fragmentation index of green vegetation of the 0-200 m buffer increased from 0.1(the minimum for the year)to 1.7(the maximum for the year)during the seven years of this study along the Fenhe River.The fragmentation index of built-up land increased from 0.007 to 0.01 in the 200-500 m buffer and from 0.007 to 0.06 in the 500-1000 m buffer.(3)The total ecosystem service value of Jinyang Lake and its buffer region decreased by 22.673%,whereas during the same period,that of the Fenhe River and its buffer region increased by 41.345%.The total ecosystem service value of the water bodies and their buffer regions in the Taiyuan urban area increased by 13.725%overall.(4)The change rate of the ecosystem service value of the 0-600 m buffer region decreased by 1.579%at Jinyang Lake,while that of the 0-1000 m buffer region increased 5.079%at the Fenhe River over the seven years.Liu Ping Zheng Xiuqing Chen Junfeng Zhang Qing Li Jingling Wu Bo 2016International Journal of Agricultural and Biological Engineering2016,9,1:3
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