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On the generation of high-quality Nyquist pulses in mode-locked fiber lasers
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作者 任俞宣 葛锦蔓 +2 位作者 李小军 彭俊松 曾和平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期424-427,共4页
Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers r... Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers remains elusive.We address this problem by managing different physical effects in mode-locked fiber lasers through extensive numerical simulations.We find that net dispersion,linear loss,gain and filter shaping can affect the quality of Nyquist pulses significantly.We also demonstrate that Nyquist pulses experience similariton shaping due to the nonlinear attractor effect in the gain medium.Our work may contribute to the design of Nyquist pulse sources and enrich the understanding of pulse shaping dynamics in mode-locked lasers. 展开更多
关键词 mode locking laser SOLITON FIBER PULSE
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The Relationship between Father-Love Absence and Loneliness:Based on the Perspective of the Social Functionalist Theory and the Social Needs Theory
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作者 Yaping Zhou He Zhong +1 位作者 xiaojun li Yanhui Xiang 《International Journal of Mental Health Promotion》 2024年第2期139-148,共10页
Fathers play an important role in adolescents’development,which is significant for their development and influences their mental health,including feeling of loneliness.However,the effects and mechanisms of father-lov... Fathers play an important role in adolescents’development,which is significant for their development and influences their mental health,including feeling of loneliness.However,the effects and mechanisms of father-love absence on individual loneliness are not clear.Based on the social functionalist theory and the social needs theory,this study examines the influence of individual fatherlove absence on loneliness and its underlying mechanisms.A questionnaire survey was administered to 319 junior high school students and 1,476 high school students.The results showed that adolescents with father-love absence had higher levels of loneliness,and that father-love absence affected loneliness levels through mediating pathways of individual gratitude,peer relationships,and gratitude to peer relationships.This study not only confirms the negative effects of father-love absence on adolescents’loneliness,but also explains the mediate roles of individual gratitude and peer relationships.It enriches the theoretical system related to family education and has important theoretical and practical implications for further interventions on adolescents’mental health from the perspective of fatherless parenting. 展开更多
关键词 Father-love absence LONELINESS GRATITUDE peer relationships
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Pulse-like ground motion observed during the 6 February 2023 M_(W)7.8 Pazarcık Earthquake(Kahramanmaraş,SE Türkiye) 被引量:2
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作者 Fan Wu Junju Xie +6 位作者 Zhao An Chenghao Lyu Tuncay Taymaz Tahir Serkan Irmak xiaojun li Zengping Wen Baofeng Zhou 《Earthquake Science》 2023年第4期328-339,共12页
In this study,we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 M_(W)7.8 Pazarcık(Kahramanmaraş)Earthquake in SE Türkiye.The wavelet... In this study,we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 M_(W)7.8 Pazarcık(Kahramanmaraş)Earthquake in SE Türkiye.The wavelet method was utilized to identify and analyze the characteristics of pulse-like ground motions in the near-fault region,while considering the uncertainty of the pulse orientation during the analysis.Our investigation focused on the effects of the focal mechanism and rupture process on the spatial distribution,pulse orientation,and maximum pulse direction of the observed pulse-like ground motion.We also analyzed the amplitude and period of the observed ground pulses and the effect of long-period amplification on the ground motion response spectra.Our results indicated the following:(1)A total of 21 typical ground velocity pulses were observed during this earthquake,exhibiting complex characteristics due to the influence of the strike-slip mechanism and rupture directivity.Most ground pulses(17 out of 21)were recorded within 20 km of the fault,in a wide range of orientations,including normal and parallel to the fault direction.The waveforms exhibited unidirectional features,indicating the effects of left-lateral fault slip.Distinct pulses observed more than 20 km from the fault were mainly oriented normal to the fault.The waveforms were bidirectional with double-or multi-round trips as a result of rupture directivity.(2)The amplitudes of the observed pulses ranged from 30.5 to 220.0 cm/s,with the largest peak velocity of 220.0 cm/s observed at Station 3138.The pulse periods ranged from 2.3 to 14.5 s,with the longest pulse period of 14.5 s observed at Station 3116.The amplitude and period of the pulses observed during this earthquake were comparable to those of similar-magnitude global earthquakes.The amplitude of the pulses decreased significantly with increasing fault distance,whereas the pulse period was not significantly affected by the fault distance.(3)Compared with non-pulse records,the velocity pulse records had a pronounced amplification effect on the acceleration response spectra near the pulse period,with factors ranging from 2.1 to 5.8.The larger velocity pulses also significantly amplified the velocity response spectra,particularly over the long periods.This significant amplification effect of the pulses on the response spectra leads to empirical models underestimating the long-period earthquake ground motion. 展开更多
关键词 2023 M_(W)7.8 Pazarcık Earthquake pulse-like ground motion response spectrum predominant period
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Baizhu-Baishao herb pair ameliorates functional constipation and intestinal microflora disorder in rats 被引量:1
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作者 xiaojun li Xiaoting Wang +1 位作者 Ziyan Wang Jiaqi Guan 《Animal Models and Experimental Medicine》 CAS CSCD 2023年第6期598-608,共11页
Background:In China,Rhizoma atractylodis macrocephalae-Paeonia lactiflora Pall(Biazhu-Baishao,BZBS)is a classic herb pair used to treat intestinal stress syndrome,ulcerative colitis and other diseases.However,the mech... Background:In China,Rhizoma atractylodis macrocephalae-Paeonia lactiflora Pall(Biazhu-Baishao,BZBS)is a classic herb pair used to treat intestinal stress syndrome,ulcerative colitis and other diseases.However,the mechanism of BZBS in the treatment of functional constipation(FC)has been little studied and remains unclear.In this study,a behavioral investigation,colon tissue morphology,enzyme-linked immunosorbent assay(Elisa)and intestinal microflora analysis have been used to illuminate the potential mechanism of the effects of BZBS on FC in a rat model.Methods:A FC rat model was constructed and BZBS was given as treatment.Observations and recordings were made of the fecal moisture content,the defecation time of the first black stool,and the rate of intestinal propulsion.Elisa was used to detect the expression levels of substance P(SP),vasoactive intestinal peptide(VIP),5-hydroxytryptamine(5-HT)in the colon.To ascertain the composition of the microbial community,a high throughput 16S ribosomal RNA(16S r RNA)gene sequencing technique was employed.Results:Oral administration of BZBS significantly ameliorated several key excretion parameters,including the time to first black stool defecation,stool water content,and the propulsion rate in the small intestine in FC rats.It increased the expression of SP,VIP and 5-HT in the colon.16S r RNA gene sequencing results showed that BZBS changed the microbial community structure,decreased the Bacteroidetes/Firmicutes ratio,increased the relative abundance of Blautia and Fusicatenibacter,and decreased the relative abundance of Ruminococcus and Roseburia.Conclusions:BZBS effectively alleviates FC and improves dysbacteriosis. 展开更多
关键词 Baizhu-Baishao functional constipation intestinal microflora
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Effects of Qigongwan on Wnt/β-catenin Signaling Pathway in Rats with Polycystic Ovary syndrome
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作者 xiaojun li Yunchao WEI +2 位作者 Haitao XIE Bin YANG Jinghong XIE 《Medicinal Plant》 CAS 2023年第4期69-73,83,共6页
[Objectives] To explore the therapeutic effect and mechanism of Qigongwan on PCOS model rats by detecting the changes in sex hormone levels in rats with polycystic ovary syndrome (PCOS), and observing the effects of o... [Objectives] To explore the therapeutic effect and mechanism of Qigongwan on PCOS model rats by detecting the changes in sex hormone levels in rats with polycystic ovary syndrome (PCOS), and observing the effects of ovarian pathological morphological changes, apoptosis and expression of Wnt/β-β catenin signaling pathway protein. [Methods] Ten of 40 female SD rats were randomly selected as the normal group, and the other 30 rats were treated with letrozole combined with high-fat diet to establish the PCOS rat model. After successful modeling, the model group was randomly divided into Qigongwan group, positive Daying-35 (Ethinylestradiol and Cyproterone Acetate Tablets) group and model group, with 10 rats in each group. Qigongwan group was given 14.7 g/(kg·d) by gavage, Daying-35 group was given 0.21 mg/(kg·d) by oral gavage, and normal group and model group were given the same amount of distilled water, and the intervention lasted for 21 d. ELISA method was used to detect the levels of hormones such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), estradiol (E 2) and progesterone (P) in serum. HE staining was used to observe the pathological morphological changes of ovarian tissues;TUNEL staining was used to observe apoptosis of ovarian tissue granule cells;the expression of Wnt, β-catenin protein in rat ovarian tissue was detected by immunohistochemistry. [Results] (i) Compared with the model group, Qigongwan group and Daying-35 group could significantly increase serum E 2 and P levels, significantly reduce serum T levels ( P <0.01), significantly reduce serum LH levels and LH/FSH ratio ( P <0.01), and increase serum FSH levels ( P <0.05) in different degrees. (ii)The results of HE staining showed that compared with the model group, Qigongwan and Daying-35 groups could improve follicular development and reduce atretic follicles in different degrees. Compared with Daying-35 group, the number of GC layers in Qigongwan group was significantly increased. (iii) The results of TUNEL staining showed that compared with the model group, the rate of TUNEL-positive cells in the Qigongwan group and Daying-35 group decreased significantly ( P <0.01). (iv) The immunohistochemical results showed that compared with the model group, the expression levels of wnt and β-catenin in the Qigongwan group and the Daying-35 group increased in different degrees ( P <0.05), and the expression range increased. [Conclusions] Qigongwan can regulate the secretion level of sex hormones such as FSH and LH, improve the pathological damage of ovarian tissue, and inhibit apoptosis of ovarian granule cells, and its mechanism may be related to the activation of Wnt/β-catenin signaling pathway. 展开更多
关键词 Qigongwan Polycystic ovary syndrome(PCOS) Granulosa cells Wnt/β-catenin signaling pathway APOPTOSIS RAT
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Technical Studies of Controlling Jujube Witches Broom Disease with Resistant Rootstock
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作者 xiaojun li Hao ZHAI +3 位作者 Jianlu QU Yong ZHANG Guangfang ZHOU Qiong ZHANG 《Plant Diseases and Pests》 CAS 2023年第2期19-22,共4页
[Objectives]The paper was to screen and identify the control effect of resistant rootstock on jujube witches broom disease.[Methods]The seeds or branches of disease-free plants were collected from wild jujube bushes i... [Objectives]The paper was to screen and identify the control effect of resistant rootstock on jujube witches broom disease.[Methods]The seeds or branches of disease-free plants were collected from wild jujube bushes infected by witches broom disease,and 5434 seedlings were obtained by sowing or cutting.The virus was inoculated by grafting diseased bark.After 6 years of preliminary screening,40 plants with resistance to jujube witches broom disease were obtained.Taking these resistant plants as the rootstocks,the susceptible variety‘long red jujube’was grafted at a height of 40 cm.When the plants grew to appropriate thickness,diseased bark was grafted to‘long red jujube’and rootstock to transmit the virus.After 18 years of observation and judgment,4 rootstock strains with high resistance or immunity to jujube witches broom disease were finally determined,namely 90801,90803,90806 and 908011.The susceptible variety‘long red jujube’was grafted to 4 rootstocks and inoculated the virus through diseased bark grafting method.[Results]The resistant rootstock had obvious disease resistance effect.When the branches of 90801 and 90803 rootstocks were grafted to the trunk of diseased trees,the symptoms of jujube witches broom disease gradually alleviated till disappeared.[Conclusions]Using germplasm with high resistance or immunity to jujube witches broom disease as rootstock can effectively prevent the spread of jujube witches broom disease,and bridging the trunk of diseased trees with branches from resistant rootstock has certain therapeutic effect. 展开更多
关键词 Jujube tree Jujube witches broom disease Prevention and control technology ROOTSTOCK
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Existence of Traveling Waves in Lattice Dynamical Systems
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作者 xiaojun li Yong Jiang Ziming Du 《Journal of Applied Mathematics and Physics》 2016年第7期1231-1236,共6页
Existence of traveling wave solutions for some lattice differential equations is investigated. We prove that there exists  c<sub>*</sub>>0 such that for each c≥c*</sub>, the systems und... Existence of traveling wave solutions for some lattice differential equations is investigated. We prove that there exists  c<sub>*</sub>>0 such that for each c≥c*</sub>, the systems under consideration admit monotonic nondecreasing traveling waves. 展开更多
关键词 Traveling Wave Lattice Dynamical Systems Schauder’s Fixed Point Theorem
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Analysis of the Influence of Oxygen Enrichment in the Blast on Temperature Field and NO_(x)Generation near the Burner in Reheating Furnace
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作者 xiaojun li Fuyong Su 《Frontiers in Heat and Mass Transfer》 EI 2024年第3期719-732,共14页
In order to study the effect of oxygen-enriched combustion technology on the temperature field and NOX emission in the continuous heating furnace,this paper studies the oxygen-enriched combustion of a pushing steel co... In order to study the effect of oxygen-enriched combustion technology on the temperature field and NOX emission in the continuous heating furnace,this paper studies the oxygen-enriched combustion of a pushing steel continuous heating furnace in a domestic company.This study utilizes numerical simulation method,establishes themathematicalmodels of flow,combustion andNOX generation combustion process in the furnace and analyzes the heat transfer process and NOX generation in the furnace under different air oxygen content and different wind ratio.The research results show that with the increase of oxygen content in the air,the combustion temperature in the furnace rises significantly,and the emission concentration of NOX increases.Furthermore,the NOX emission concentration is related to the proportion of primary and secondary air. 展开更多
关键词 Oxygen-enriched combustion heating furnace numerical simulation
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Heat-fluid-solid coupling model for gas-bearing coal seam and numerical modeling on gas drainage promotion by heat injection 被引量:5
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作者 Ruifu Yuan Chunling Chen +1 位作者 Xiao Wei xiaojun li 《International Journal of Coal Science & Technology》 EI 2019年第4期564-576,共13页
Improving the absorbed gas to active desorption and seepage and delaying gas drainage attenuation are considered as key methods for increasing drainage efficiency and gas output.According to the solid mechanics theory... Improving the absorbed gas to active desorption and seepage and delaying gas drainage attenuation are considered as key methods for increasing drainage efficiency and gas output.According to the solid mechanics theory,the nonlinear Darcy seepage theory and thermodynamics,the heat-fluid-solid coupling model for gassy coal has been improved.The numerical model was founded from the improved multi-field coupling model by COMSOL Multiphysics and gas drainage by borehole down the coal seam enhanced by heat injection was modelled.The results show that the heatfluid-solid model with adsorption effects for gassy coal was well simulated by the improved multi-field model.The mechanism of coal seam gas desorption seepage under the combined action of temperature,stress and adsorption can be well described.Gas desorption and seepage can be enhanced by heat injection into coal seams.The gas drainage rate was directly proportional to the temperature of injected heat in the scope of 30-150 ℃ and increasing in the whole modelleddrainage process (0-1000 d).The increased level was maximum in the initial drainage time and decreasing gradually along with drainage time.The increasing ratio of drainage rate was maximum when the temperature raised from 30 to 60 ℃.Although the drainage rate would increase along with increasing temperature,when exceeding 60 ℃,the increasing ratio of drainage rate with rising temperature would decrease.Gas drainage promotion was more effective in coal seams with lower permeability than with higher permeability.The coal seam temperature in a 5 m distance surrounding the heat injection borehole would rise to around 60 ℃ in 3 months.That was much less than the time of gas drainage in the coal mines in sites with low permeability coal seams.Therefore,it is valuable and feasible to inject heat into coal seams to promote gas drainage,and this has strong feasibility for coal seams with low permeability which are widespread in China. 展开更多
关键词 Gassy COAL Heat-fluid-solid coupling model Heat injection GAS extraction Numerical modeling
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Controlling Ion Conductance and Channels to Achieve Synapticlike Frequency Selectivity 被引量:1
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作者 Siheng Lu Fei Zeng +3 位作者 Wenshuai Dong Ao liu xiaojun li Jingting Luo 《Nano-Micro Letters》 SCIE EI CAS 2015年第2期121-126,共6页
Enhancing ion conductance and controlling transport pathway in organic electrolyte could be used to modulate ionic kinetics to handle signals. In a Pt/Poly(3-hexylthiophene-2,5-diyl)/Polyethylene?Li CF3SO3/Pt hetero-j... Enhancing ion conductance and controlling transport pathway in organic electrolyte could be used to modulate ionic kinetics to handle signals. In a Pt/Poly(3-hexylthiophene-2,5-diyl)/Polyethylene?Li CF3SO3/Pt hetero-junction, the electrolyte layer handled at high temperature showed nano-fiber microstructures accompanied with greatly improved salt solubility. Ions with high mobility were confined in the nano-fibrous channels leading to the semiconducting polymer layer,which is favorable for modulating dynamic doping at the semiconducting polymer/electrolyte interface by pulse frequency.Such a device realized synaptic-like frequency selectivity, i.e., depression at low frequency stimulation but potentiation at high-frequency stimulation. 展开更多
关键词 Ions migration Nano-channels Frequency selectivity Semiconducting polymer Organic electrolyte Dynamic doping
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Determination and application of path duration of seismic ground motions based on the K-NET data in Sagami Bay,Japan
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作者 Shiyang Chen xiaojun li +1 位作者 Lei Fu Su Chen 《Earthquake Science》 2022年第4期263-279,共17页
Duration models are one of the important parameters in ground-motion simulations.This model varies in different study areas,and plays a critical role in nonlinear structural response analysis.Currently,available empir... Duration models are one of the important parameters in ground-motion simulations.This model varies in different study areas,and plays a critical role in nonlinear structural response analysis.Currently,available empirical models are being globally used in ground-motion simulations,with limited research focusing on path duration in specific regions.In this study,we collected 6,486 sets of three-component strong-motion records from 29 K-NET stations in the Sagami Bay,Japan,and its surrounding areas between January 2000 to October 2018.We extracted the effective duration of 386 pieces of ground-motion records by manually picking up the S-wave arrival time and calculating the significant duration.We then obtained the path duration model of the study area based on the empirical equation of dynamic corner frequency and source duration of Boore(2009).Compared with the results of the available empirical models,the Fourier spectrum of the simulated ground motion from our effective duration model showed higher accuracy in the long-term range,with less fitting residuals.This path duration model was then applied to simulate two earthquakes of M_(W)5.4 and M_(W)6.2,respectively,in the region using the stochastic finite-fault method with a set of reliable source,path,and site parameters determined for the study area.The simulation results of most stations fit well with observation records in the 0-30 Hz frequency band.For the M_(W)5.4 earthquake,the simulated ground motions at KNG005/KNG010/SZO008 stations were relatively weak in the mid to high frequency band(1-30 Hz)because the quality factor and geometric diffusion model used in the simulation were the averages of the entire Sagami Bay region,causing a bias in the results of a few stations owing to local crustal velocity anomalies and topographic effects.For the M_(W)6.2 earthquake,the simulated ground motions were relatively weak at all SZO and TKY stations,mainly because of the close distance from these stations to the epicenter and the complex seismic-wave propagation paths.The analysis suggests that the differences between the simulation results of the two earthquakes were mainly related to complex geological conditions and seismic-wave propagation paths. 展开更多
关键词 Sagami Bay path duration effective duration stochastic finite-fault method
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A CORBA Replication Voting Mechanism for Maintaining the Replica Consistent
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作者 Guohua WU xiaojun li +1 位作者 Qiuhua ZHENG Zhen ZHANG 《Journal of Software Engineering and Applications》 2009年第4期276-282,共7页
Nowadays, more and more applications are being developed through distributed object computing middleware, such as CORBA, their requirements for fault-tolerance, especially real time and critical system, become more an... Nowadays, more and more applications are being developed through distributed object computing middleware, such as CORBA, their requirements for fault-tolerance, especially real time and critical system, become more and more critical. Despite almost ten years have passed since the earliest FT-CORBA standard was promulgated by Object Management Group (OMG), CORBA is still facing many challenges when it is used for distributed applications developing, as the standard is complex and lack of understanding. This paper focus on the consistency of the replicated object and the network partition problem, it incorporates a CORBA Replication Voting Mechanism (CRVM) to meet the challenge which makes a good performance. 展开更多
关键词 distributed computing CRVM FAULT-TOLERANCE REPLICA CONSISTENT NETWORKING PARTITION
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Genome-wide characterization of graft-transmissible mRNA-coding P450 genes of cucumber(Cucumis sativus L.) 被引量:1
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作者 Tao Wang Xiaohong Lu +6 位作者 Chenggang Xiang xiaojun li Wenqian liu QingWang Zixi liu lihong Gao Wenna Zhang 《Horticultural Plant Journal》 SCIE CAS CSCD 2023年第2期250-260,共11页
P450(cytochrome P450)is a supergene family,which is involved in various metabolic pathways in plants.Based on previous study,we found some of cucumber P450 mRNAs were systemic mobile in cucumber/pumpkin grafts.However... P450(cytochrome P450)is a supergene family,which is involved in various metabolic pathways in plants.Based on previous study,we found some of cucumber P450 mRNAs were systemic mobile in cucumber/pumpkin grafts.However,the reason that why P450 mRNAs were endorsed as signaling,and what specific motif(s)did they harbored is not clear yet.Here,we first identified 221 CsaP450 genes in cucumber genomewide level.Combining with graft-transmissiblemRNAs datasets in cucumber,we elucidated 15mobile-CsaP450-coding genes,of which 5 and 10 belonged to A-type and non-A type respectively.Compared with Arabidopsis and pumpkin(Cucubit moschata)graft-induced-transmissible P450 mRNAs,a phylogenetic treewas constructed and divided into eight clans by usingmultiple-sequence alignment.Gene ontology(GO)enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)annotations indicated that the expression patterns of the mobile-mRNA-coding CsaP450 genes in different tissues of cucumber was specifically enriched in oxidoreductase activity and secondary metabolic pathways.The structures and motifs of these 15 mobile-mRNA-coding CsaP450 genes and their types of regulatory elements told that the proportion of CU-rich motifs was higher than nonmobile-mRNA-coding CsaP450 genes.The integrated analysis of mobility direction and mRNA abundance of 15 mobilemRNA-coding CsaP450 genes allowed to conclude that there was rarely relationship between them.The study provided a new insight into the relationship between the motifs and functional characterization of mobile-mRNA-coding P450 genes of cucumber in genome-wide levels. 展开更多
关键词 Cucumis sativus GENOME-WIDE Cytochrome P450 mRNA mobility Phylogeny CU-rich motif
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Multi-source data integration and multi-scale modeling framework for progressive prediction of complex geological interfaces in tunneling 被引量:2
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作者 Jingxiao Wang Peinan li +3 位作者 Xiaoying Zhuang xiaojun li Xi Jiang Jun Wu 《Underground Space》 SCIE EI CSCD 2024年第2期1-25,共25页
A reliable geological model plays a fundamental role in the efficiency and safety of mountain tunnel construction.However,regional models based on limited survey data represent macroscopic geological environments but ... A reliable geological model plays a fundamental role in the efficiency and safety of mountain tunnel construction.However,regional models based on limited survey data represent macroscopic geological environments but not detailed internal geological characteristics,especially at tunnel portals with complex geological conditions.This paper presents a comprehensive methodological framework for refined modeling of the tunnel surrounding rock and subsequent mechanics analysis,with a particular focus on natural space distortion of hard-soft rock interfaces at tunnel portals.The progressive prediction of geological structures is developed considering multi-source data derived from the tunnel survey and excavation stages.To improve the accuracy of the models,a novel modeling method is proposed to integrate multi-source and multi-scale data based on data extraction and potential field interpolation.Finally,a regional-scale model and an engineering-scale model are built,providing a clear insight into geological phenomena and supporting numerical calculation.In addition,the proposed framework is applied to a case study,the Long-tou mountain tunnel project in Guangzhou,China,where the dominant rock type is granite.The results show that the data integration and modeling methods effectively improve model structure refinement.The improved model’s calculation deviation is reduced by about 10%to 20%in the mechanical analysis.This study contributes to revealing the complex geological environment with singular interfaces and promoting the safety and performance of mountain tunneling. 展开更多
关键词 Mountain tunnel Geological modeling Multi-source data Progressive prediction Tunnel portals
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Probabilistic prediction on three-dimensional roughness of discontinuity based on two-dimensional traces under rock tunnel excavation based on Bayesian theory
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作者 Qi Zhang Yuechao Pei +2 位作者 xiaojun Wang xiaojun li Yixin Shen 《Underground Space》 SCIE EI CSCD 2024年第1期338-356,共19页
Three-dimensional(3D)roughness of discontinuity affects the quality of the rock mass,but 3D roughness is hard to be measured due to that the discontinuity is invisible in the engineering.Two-dimensional(2D)roughness c... Three-dimensional(3D)roughness of discontinuity affects the quality of the rock mass,but 3D roughness is hard to be measured due to that the discontinuity is invisible in the engineering.Two-dimensional(2D)roughness can be calculated from the visible traces,but it is difficult to obtain enough quantity of the traces to directly derive 3D roughness during the tunnel excavation.In this study,a new method using Bayesian theory is proposed to derive 3D roughness from the low quantity of 2D roughness samples.For more accurately calculating 3D roughness,a new regression formula of 2D roughness is established firstly based on wavelet analysis.The new JRC3D prediction model based on Bayesian theory is then developed,and Markov chain Monte Carlo(MCMC)sampling is adopted to process JRC3D prediction model.The discontinuity sample collected from the literature is used to verify the proposed method.Twenty groups with the sampling size of 2,3,4,and 5 of each group are randomly sampled from JRC2D values of 170 profiles of the discontinuity,respectively.The research results indicate that 100%,90%,85%,and 60%predicting JRC3D of the sample groups corresponding to the sampling size of 5,4,3,and 2 fall into the tolerance interval[JRC_(true)–1,JRC_(true)+1].It is validated that the sampling size of 5 is enough for predicting JRC3D.The sensitivities of sampling results are then analyzed on the influencing factors,which are the correlation function,the prior distribution,and the prior information.The discontinuity across the excavation face at ZK78+67.5 of Daxiagu tunnel is taken as the tunnel engineering application,and the results further verify that the predicting JRC3D with the sampling size of 5 is generally in good agreement with JRC3D true values. 展开更多
关键词 Rock discontinuity Joint roughness coefficient Tunnel excavation Bayesian theory Markov chain Monte Carlo sampling
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A modified method of discontinuity trace mapping using three-dimensional point clouds of rock mass surfaces 被引量:13
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作者 Keshen Zhang Wei Wu +3 位作者 Hehua Zhu lianyang Zhang xiaojun li Hong Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2020年第3期571-586,共16页
This paper presents an automated method for discontinuity trace mapping using three-dimensional point clouds of rock mass surfaces.Specifically,the method consists of five steps:(1)detection of trace feature points by... This paper presents an automated method for discontinuity trace mapping using three-dimensional point clouds of rock mass surfaces.Specifically,the method consists of five steps:(1)detection of trace feature points by normal tensor voting theory,(2)co ntraction of trace feature points,(3)connection of trace feature points,(4)linearization of trace segments,and(5)connection of trace segments.A sensitivity analysis was then conducted to identify the optimal parameters of the proposed method.Three field cases,a natural rock mass outcrop and two excavated rock tunnel surfaces,were analyzed using the proposed method to evaluate its validity and efficiency.The results show that the proposed method is more efficient and accurate than the traditional trace mapping method,and the efficiency enhancement is more robust as the number of feature points increases. 展开更多
关键词 Rock mass DISCONTINUITY Three-dimensional point clouds Trace mapping
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Seismic response analysis of continuous rigid frame bridge considering canyon topography effects under incident SV waves 被引量:8
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作者 Guoliang Zhou xiaojun li Xingjun Qi 《Earthquake Science》 CSCD 2010年第1期53-61,共9页
To evaluate the importance of the canyon topography effects on large structures, based on a rigid frame bridge across a 137-m-deep and 600-m-wide canyon, the seismic response of the canyon site is analyzed using a two... To evaluate the importance of the canyon topography effects on large structures, based on a rigid frame bridge across a 137-m-deep and 600-m-wide canyon, the seismic response of the canyon site is analyzed using a two-dimensional finite element model under different seismic SV waves with the assumptions of vertical incidence and oblique incidence to obtain the ground motions, which are used as the excitation input on the pier foundations of the bridge with improved large mass method. The results indicate that canyon topography has significant influences on the ground motions in terms of inci- dent angle. The peak ground acceleration values vary greatly from the bottom of the canyon to the upper comers. Under ver- tical incident SV waves, at the upper comers of canyon the peak ground accelerations greatly increase; whereas the peak ground accelerations diminish at the bottom comers of canyon. Under oblique incident SV waves, the shaking of the canyon slope perpendicular to the incidence direction is much more severe than that of the opposite side of canyon. And the ground surface has been characterized by larger deformations in the case of oblique incident waves. It is also concluded that the low piers and frame of the continuous rigid frame bridge ape more sensitive to the multi-support seismic excitations than the flexible high piers. The canyon topography as well as the oblique incidence of the waves brings the continuous rigid frame bridge severe responses, which should be taken into account in bridge design. 展开更多
关键词 rigid frame bridge canyon topography effect multi-support excitation improved large-mass method seismic response
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Ground motion attenuation of M_s8.0 Wenchuan earthquake 被引量:6
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作者 Dawei Lu Jianwen Cui +1 位作者 xiaojun li Weiping lian 《Earthquake Science》 CSCD 2010年第1期95-100,共6页
The great Ms8.0 Wenchuan earthquake has been the most destructive earthquake since 1949 in China. The earthquake occurred no more than half a year after the establishment of the National Strong Motion Observation Netw... The great Ms8.0 Wenchuan earthquake has been the most destructive earthquake since 1949 in China. The earthquake occurred no more than half a year after the establishment of the National Strong Motion Observation Network System (NSMONS) of China; what is more, the epicenter was located in the area with dense strong motion observation sta- tions so that a large number of strong motion records of the main shock were obtained. In this paper, 501 strong motion re- cords from 167 observation stations are utilized to establish the ground motion attenuation relations in three directions in the range of fault distance less than 600 km. The result shows the difference of seismic motion attenuation in two horizontal di- rections is insignificant. It is the first time that strong-motion records are used to establish the ground motion attenuation relations of the Ms8.0 earthquake in China. 展开更多
关键词 Wenchuan earthquake strong motion record ground motion attenuation response spectrum
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Correlation of ADC value with pathologic indexes in colorectal tumor homografts in Balb/c mouse 被引量:4
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作者 xiaojun li Hongnan Jiang +1 位作者 Jinliang Niu Ying Zheng 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2014年第4期444-450,共7页
Objective: Noninvasive diffusion-weighted magnetic resonance imaging (DWI) is a well-studied MR imaging technique for quantifying water diffusion especially in tumor area. The correlation between apparent diffusion... Objective: Noninvasive diffusion-weighted magnetic resonance imaging (DWI) is a well-studied MR imaging technique for quantifying water diffusion especially in tumor area. The correlation between apparent diffusion coefficient (ADC) value and apoptosis or proliferation is not clear by now. This study aimed to investigate whether DWI-ADC value could be used as an imaging marker related with pathologic indexes of tumors. Methods: A total of 3 0 Balb/c mice with HT2 9 colorectal carcinoma were subjected to DWI and histologic analysis. The percentage of ADC changes and the apoptotic and proliferating indexes were calculated at predefined time points. Kolmogorov-Smirnov distances were considered to determine whether the percentage of ADC changes, and the apoptotic and proliferating indexes were normally distributed. An independent-samples t-test was used to analyze the difference between apoptotic and proliferating indexes in the two groups. Results: There was a statistically significant difference in proliferating index between the radiotherapy and control groups (mean proliferating index: 49.27% vs. 83.09%), and there was a statistically significant difference in apoptotic index between the two groups (mean apoptotic index: 37.7% vs. 2.71%). A significant positive correlation was found between the percentage of ADC changes of the viable tissue and apoptotic index. Pearson's correlation coefficient was 0.655 (P=0.015). A significant negative correlation was found between the percentage of ADC changes of the viable tissue and ki-67 proliferation index. Pearson's correlation coefficient was 0.734 (P〈0.001). Conclusions: Our results suggest that ADC proliferating indexes in colorectal carcinoma. value may be used in measurement of cell apoptotic and 展开更多
关键词 Diffusion-weighted magnetic resonance imaging (DWI) apparent diffusion coefficient (ADC) apoptosis proliferation HT29
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Network pharmacological prediction and molecular docking analysis of the combination of Atractylodes macrocephala Koidz.and Paeonia lactiflora Pall.in the treatment of functional constipation and its verification 被引量:4
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作者 Yuxiao Meng xiaojun li +2 位作者 Xiaoting Wang Lu Zhang Jiaqi Guan 《Animal Models and Experimental Medicine》 CSCD 2022年第2期120-132,共13页
Background:We aimed to reveal the mechanism of functional constipation in the treatment of Atractylodes macrocephala Koidz.(AMK)and Paeonia lactiflora Pall.(PLP).Methods:The main active ingredients of AMK and PLP were... Background:We aimed to reveal the mechanism of functional constipation in the treatment of Atractylodes macrocephala Koidz.(AMK)and Paeonia lactiflora Pall.(PLP).Methods:The main active ingredients of AMK and PLP were screened by the Traditional Chinese Medicine Systems Pharmacology(TCMSP)platform.A database of functional constipation targets was established by GeneCard and OMIM.An“ingredient-target”network map was constructed with Cytoscape software(version 3.7.1),and molecular docking analysis was performed on the components and genes with the highest scores.The rats in the normal group were given saline,and those in the other groups were given 10 mg/kg diphenoxylate once a day for 14 days.The serum and intestinal tissue levels of adenosine monophosphate(cAMP),protein kinase A(PKA),and adenylyl cyclase(AC)of the rats and aquaporin(AQP)1,AQP3,and AQP8 were measured.Results:AMK and PLP had a significant role in the regulation of targets in the treatment of functional constipation.After treatment with AMK,PLP,or mosapride,the serum and intestinal tissue levels of AC,cAMP,and PKA were significantly downregulated.Groups receiving AMK and PLP or mosapride exhibited a reduction in the level of AQP1,AQP3,and AQP8 to varying degrees.Conclusion:Molecular docking analysis revealed that AMK and PLP had a significant role in the regulation of targets in the treatment of functional constipation.Studies have confirmed that AMK and PLP can also affect AC,cAMP,and PKA.AC,cAMP,and PKA in model rats were significantly downregulated.AQP expression is closely related to AC,cAMP,and PKA.AMK and PLP can reduce the expression of AQP1,AQP3,and AQP9 in the colon of constipated rats. 展开更多
关键词 coupling of AMK and PLP functional constipation mechanism network pharmacology
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