检索结果-南通市图书馆

Water Science and Engineering 2024年第2期17卷 129-138页

作者： Guo-fen Hua Shang-qing liu xiang-dong liu Jin-li Li Yue Fang Wen-ting Xie xiang Xu College of Water Conservancy and Hydroelectric Power Hohai UniversityNanjing 210098China College of Renewable Energy Hohai UniversityNanjing 210098China

Coastal wetlands are hotspots for nitrogen(N)cycling,and crab burrowing is known to transform N in intertidal marsh soils.However,the underlying mechanisms remain unclear.This study conducted field experiments and used indoor control test devices to investigate the seasonal response of nitrogen to crab disturbance at the sediment-water interface in coastal tidal flat wetlands.The results showed that crab disturbance exhibited significant seasonality with large seasonal differences in cave density and depth.Due to crab disturbance,nitrogen fuxes at the sediment-water interface were much greater in the box with crabs than in the box without crabs.In summer,NH-N showed a positive flux from the sediment to the overlying water,but NO2-N and NOg-N showed positive fluxes from the sediment to the overlying water only in early stages.In winter,NH-N showed a positive flux from the sediment to the overlying water,but NO-N and NO,-N both exhibited positive and negative fluxes.These results indicated that the presence of crab burrows can cause the aerobic layer to move downward by approximately 8-15 cm in summer and directly promote nitrification at the sediment surface.

关键词： Coastal tidal flat wetland Crab disturbance Nitrogen flux Nitrification Denitrification Sediment-water interface

Relative contribution of genetic and environmental factors to determination of wing morphs of the brown planthopper Nilaparvatalugens

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2023年第1期30卷 208-220页

作者： Chao Zhang Meng-Sha Mao xiang-dong liu Department of Entomology Nanjing Agricultural UniversityNanjingChina

Wing dimorphism is a fascinating feature of the ability of insects to adapt to environments.The brown planthopper(BPH)Nilaparvata lugens,a serious pest of rice,can switch between the long-and short-winged morphs.It has been known that environmental factors can affect the wing morph of BPH.However,it is still unclear whether the effect of environment is dependent on BPH genetic backgrounds or not.In the present study,we established the pure-bred lineages of short-and long-winged BPHs via multigenerational selection,and we found that survival and fecundity were similar between these 2 lineages.Wing morphs of the pure-bred lineages were almost fully dependent on genetics,but independent of the environmental factors,nymphal density and rice plant stage,2 key factors affecting BPH wing morphs.In the unselected BPH population,short-and longwinged morphs were produced depending on those 2 environmental factors,indicating the contribution of environment to wing morph.In the wing-selected lineages,4 developmental regulated genes of wing,NllnRI,NllnR2,NIAkt,and NIFoxo were expressed stably in the short-winged adults,but almost silenced in the long-winged adults.However,all these genes were expressed normally with a similar level in both the short-and long-winged adults in an unselected population except NlFoxo.The pure-bred lineages of long-and short-winged morphs exhibited different expression patterns of wing development-regulated genes,suggesting the genetic determination of wing morphs.Effects of environmental factors on wing morphs occurred only in the genetic mix population.

关键词： environmental effect gene expression genetic determination Nilaparvata lugens pure-bred lineage wing dimorphism

A.S.Convergence Rate and L^(p)-Convergence of Bisexual Branching Processes in a Random Environment and Varying Environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2023年第2期39卷 337-353页

作者： Sheng XIAO xiang-dong liu Ying-qiu LI School of economics Jinan UniversityGuangzhou510632China School of Mathematics and Statistics Changsha University of Science and TechnologyChangsha 410004China Hunan Provincial Key Laboratory of Mathematical Modeling and Analysis in Engineering Changsha University of Science and TechnologyChangsha 410004China

Let(Z_(n))be a supercritical bisexual branching process in a random environmentξ.We study the almost sure(a.s.)convergence rate of the submartingale W_(n)=Z_(n)/In to its limit W,where(In)is an usually used norming sequence.We prove that under a moment condition of order p∈(1,2),W-W_(n)=o(e^(-na))a.***.for some a>0 that we find explicitly;assuming the logarithmic moment condition holds,we haveW-W_(n)=o(n^(-α))a.s..In order to obtain these results,we provide the L^(p)-convergence of(W_(n));similar conclusions hold for a bisexual branching process in a varying environment.

关键词： bisexual branching process convergence rate varying environment random environment

A foot structure study of new arch flexibility grading system based on threedimensional arch volume

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Traumatology 2023年第6期26卷 329-333页

作者： Jun liu Miao Deng Wei Wang xiang-dong liu Lun Tao Hong-Yi xiang Yan Xiong Department of Orthopedics Daping HospitalArmy Medical UniversityChongqing400042China The 5th Outpatient Clinic Western Theater General HospitalChengdu610000China Department of Orthopedics Armed Police Hospital of ChongqingChongqing400042China Institute for Traffic Medicine Daping HospitalArmy Medical UniversityChongqing400042China

Purpose:Different arch structures may cause different foot function injuries.In the past,the arch structure and flexibility of the foot were often defined by the height of the arch,and there was no three-dimensional(3D)structure classification method.In order to form a more complete 3D description,we propose a new classification system of arch volume flexibility(AVF),and then use this new classification system to investigate the relationship between the AVF and arch index(AI),and the arch height flexibility(AHF)and AI,respectively.Methods:It is proposed to recruit 180 young male adults for the test.We obtained arch volume and AI through 3D scanning and obtained the navicular height through manual measurement.Based on these data,we calculated the AHF and the AVF.Using the quintile method,these arches are divided into very stiff,stiff,neutral,flexible,and very flexible.According to AI value,all arches were divided into cavus,rectus,and planus.The distribution of AVF was compared usingχ^(2)goodness of fit test.The spearman correlation test was used to compare the AHF and AVF.A p<0.05 indicates that the difference is statistically significant.Results:All participants'plantar data was obtained through 3D scanning,but only 159 of them were complete,so only 318 feet had valid data.The left AHF is(21.23±12.91)mm/kN,and the right AHF is(21.71±12.69)mm/kN.The AVF of the left foot arch is(207.35±118.28)mm^(3)/kg,while the right one is(203.00±117.92)mm^(3)/kg,and the total AVF of the arch was(205.17±117.94)mm^(3)/kg.There was no statistical difference in the AVF between the left and right feet for the same participant(n=159,p=0.654).In cavus,the percentage of arch with AVF is 21.4%(very stiff),21.4%(stiff),14.3%(neutral),7.1%(flexible),and 35.7%(very flexible).In rectus,the percentage of arch with AVF is 23.9%(very stiff),19.6%(stiff),14.7%(neutral),24.5%(flexible),and 17.2%(very flexible).In planus,the percentage of arch with AVF is 14.9%(very stiff),20.6%(stiff),27.0%(neutral),16.3%(flexible),and 21.3%(very flexible).Moreo

关键词： Arch height flexibility Arch volume flexibility Classification Arch volume Three-dimensional Arch index

Extension of the rotating dipole model with oblateness of both primaries

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第1期17卷 11-20页

作者： xiang-Yuan Zeng xiang-dong liu Jun-Feng Li School of Automation Beijing Institute of Technology School of Aerospace Engineering Tsinghua University

A rotating mass dipole can be used to understand the dynamical behaviors around elongated asteroids as well as binary asteroids. In this paper an improved dipole model with oblateness in both primaries is investigated. The dynamical equations of a particle around the improved model are first derived by introducing the oblateness coefficients. The characteristic equations of equilibrium points are obtained, resulting in the emergence of new equilibria in the equatorial plane and the plane xoz de- pending on the shape of the spheroid. Numerical simulations are performed to illustrate the distribution of these equilibrium points. Significant influence from the oblateness of the primaries on the topological structure is also analyzed via zero-velocity curves.

关键词： celestial mechanics - minor planets, asteroids general - methods numerical

Macular laser photocoagulation with or without intravitreal triamcinolone pretreatment for diabetic macular edema： a result from five randomized controlled trials

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2016年第1期9卷 132-138页

作者： xiang-dong liu Xiao-dong Zhou Zhi Wang Yong-Ming Shen Department of Ophthalmology Affiliated Jinshan HospitalFudan University Shanghai 201508 China

AIM：To assess possible benefits of intravitreal triamcinolone acetonide（IVTA）injection as pretreatment for macular laser photocoagulation（MLP）in patients with diabetic macular edema（DME）.·METHODS：Published randomized controlled trials（RCTs）concerning MLP with or without IVTA pretreatment for DME were retrieved from databases CNKI,Medline,EMbase,Web of Science,and the Cochrane Library.A Meta-analysis on eligible studies was conducted using Rev Man 5.0 software.Two investigators independently assessed the quality of the trials and extracted data.Main outcome measures included the change in best-corrected visual acuity（BCVA）,difference in central macular thickness（CMT）and adverse events reporting in particular elevated intraocular pressure within the follow-up period.The results were pooled using weight mean difference（WMD）or odds risk（OR）with their corresponding 95%confidence intervals（CI）.A fixed-or random-effect model was employed depending on the heterogeneity of the inclusion trials.·R ESULTS：Finally,five independent RCTs were identified and used for comparing MLP with IVTA pretreatment（131 eyes）with MLP alone（133 eyes,control group）.The overall study quality was relatively higher according to the modified Jadad scale.The Metaanalysis showed that MLP with IVTA pretreatment significantly reduced CMT at one,three and six months（=0.002,0.0003 and 0.04,respectively）,compared with MLP alone.The IVTA pretreatment group showed statistically significant improvements in BCVA at the one-month follow up as compared with the control group（=0.03）.At three-and six-month follow up,there was a beneficial trend towards improving visual acuity in the IVTA pretreatment group without statistical significance between groups（=0.06 and 0.20,respectively）.The incidence of elevation of intraocular pressure was significantly higher in the IVTA pretreatment group than in the control group（〈0.0001）.No evidence of publication bias was present according to Begg’s test and Egger’s test.There was a low level of heterogeneity in the included s

关键词： photocoagulation intravitreal injection triamcinolone acetonide diabetic macular edema

Comparison of intravitreal bevacizumab with macular photocoagulation for treatment of diabetic macular edema: a systemic review and Meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2014年第6期7卷 1048-1055页

作者： xiang-dong liu Xiao-dong Zhou Zhi Wang Hong-Jie Shen Department of Ophthalmology Affiliated Jinshan HospitalFudan University

AIM: To further evaluate the efficacy and safety of intravitreal bevacizumab(IVB) versus macular photocoagulation(MPC) in treatment of diabetic macular edema(DME) by Meta-analysis. METHODS: Pertinent publications were identified through systemic searches of Pub Med, Medline,EMBASE, and the Cochrane Controlled Trials Register up to 30 November, 2013. Changes in central macular thickness(CMT) in μm and best-corrected visual acuity(BCVA) in log MAR equivalents were extracted at 1, 3, 6,12 and 24 mo after initial treatment, and a Meta-analysis was carried out to compare results between groups receiving IVB and MPC.RESULTS: Five randomized controlled trial(RCTs) and one high-quality comparative study were identified and included. Our Meta-analysis revealed that both IVB and MPC resulted in the improvements of CMT and BCVA in eyes with DME at 1mo after initial treatment, with IVB being significantly superior to MPC(P =0.01 and 0.02,respectively). The improvements of both measure outcomes at 3, 6, 12 and 24 mo after treatment did not vary significantly between the IVB groups and MPC groups(CMT at 3mo, P =0.85; at 6mo, P =0.29; at 12 mo,P =0.56; at 24 mo, P =0.71; BCVA at 3mo, P =0.31; at 6mo,P =0.30; at 12 mo, P =0.23; at 24 mo, P =0.52). However,the number of observed adverse events was low in all studies.CONCLUSION: Current evidence shows IVB treatment trends to be more effective in improvements of macular edema and vision in eyes with DME at an earlier follow up(1mo) compared with MPC. At other time, both interventions have comparable efficacy without statistical significances.

关键词： intravitreal injection bevacizumab photocoagulation diabetic macular edema Meta-analysis

Preparation and Characterization of UV-absorbing PVDF Membranes via Pre-irradiation Induced Graft Polymerization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2019年第5期37卷 493-499页

作者： Li dong xiang-dong liu Zheng-Rong Xiong De-Kun Sheng Yan Zhou Yu-Ming Yang Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Science and Technology of China

Herein, excellent UV-absorbing poly(vinylidene fluoride)(PVDF) membranes were fabricated through the pre-irradiation induced graft polymerization method. The PVDF chains irradiated with ^(60)Co γ-ray were modified with the polymerizable UV absorber 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2 H-benzotriazole(RUVA-93). The influences of irradiation dose and monomer concentration on the prepared PVDF-g-PRUVA-93 membranes were investigated, and the optimal condition was eventually obtained. The chemical structures of the films were studied by ~1H-NMR, FTIR, and XRD. UV light transmittance and DSC tests were used to characterize the UV-absorbing performance and thermal property of the PVDF films before and after modification. The results proved that the PRUVA-93 side chains were successfully incorporated into the PVDF main chains and the obtained PVDF-g-PRUVA-93 films possessed remarkable UV-absorbing property. The modified membrane made under the optimized experiment condition could completely block the UV light in the range of 200-387 nm. Additionally, the transmittance of the PVDF-g-PRUVA-93 film could be reduced to0.04% in 280-320 nm, where the light irradiation could damage polymer materials most seriously.

关键词： PVDF membrane Modification Irradiation Grafting UV-absorbing

Bending strength and fracture surface topography of natural fiber-reinforced shell for investment casting process

在线全文

学校读者我要写书评

暂无评论

China Foundry 2016年第3期13卷 211-216页

作者： Kai Lü xiang-dong liu Zhao-xin Du Yan-fen Li School of Materials Science and Engineering inner Mongolia University of Technology Hohhot 010051 China Key Laboratory of Materials Processing & Control Engineering of Inner Mongolia Autonomous Region Hohhot 010051 China

In order to improve the properties of silica sol shell for investment casting process, various contents of cattail fibers were added into the slurry to prepare a fiber-reinforced shell in the present study. The bending strength of fiber-reinforced shell was investigated and the fracture surfaces of shell specimens were observed using SEM. It is found that the bending strength increases with the increase of fiber content, and the bending strength of a green shell with 1.0 wt.% fiber addition increases by 44% compared to the fiber-free shell. The failure of specimens of the fiber-reinforced green shell results from fiber rupture and debonding between the interface of fibers and adhesive under the bending load. The micro-crack propagation in the matrix is inhibited by the micro-holes for ablation of f ibers in specimens of the f iber-reinforced shell during the stage of being fired. As a result, the bending strength of specimens of the fired shell had no significant drop. Particularly, the bending strength of specimens of the fired shell reinforced with 0.6wt.% fiber reached the maximum value of 4.6 MPa.

关键词： fiber-reinforced shell investment casting bending strength fracture surface topography

Geology and mineralization of the Dayin’gezhuang supergiant gold deposit(180 t)in the Jiaodong Peninsula,China:A review

在线全文

学校读者我要写书评

暂无评论

China Geology 2022年第4期5卷 696-721页

作者： xiang-dong liu Zheng-jiang Ding Ming-chun Song Ming-ling Zhou Shao-hui Xu Zhen-liangYang Tian-ci Xie Tao Cui Ying-xin Song Xue-kan Gao Rui-xiang Li Liang-liang Zhang Qi-bin Zhang Shan-shan Wang Bin Wang No.6 Geological Team of Shandong Provincial Bureau of Geology and Mineral Resources Weihai 264209China Ministry of Natural Resources Technology Innovation Center for Deep Gold Resources Exploration and Mining Weihai 264209China State Key Laboratory of Geological Process and Mineral Resources China University of Geosciences(Beijing)Beijing 100083China Hebei Key Laboratory of Strategic Critical Mineral Resources Hebei GEO UniversityShijiazhuang 050031China Shandong Institute of Geological Sciences Jinan 250013China Dayin’gezhuang Gold Company Zhaojin Mining Co.Ltd.Zhaoyuan 264000China

The Dayin’gezhuang gold deposit is located in the central part of the Zhaoping Fault metallogenic belt in the Jiaodong gold province-the world’s third-largest gold metallogenic area.It is a typical successful case of prospecting at a depth of 500-2000 m in recent years,with cumulative proven gold resources exceeding 180 t.The main orebodies(No.1 and No.2 orebody)generally have a pitch direction of NNE and a plunge direction of NEE.As the ore-controlling fault,the Zhaoping Fault is a shovel-shaped stepped fault,with its dip angle presenting stepped high-to-low transitions at the elevation of -2000-0 m.The gold mineralization enrichment area is mainly distributed in the step parts where the fault plane changes from steeply to gently,forming a stepped metallogenic pattern from shallow to deep.It can be concluded from previous studies that the gold mineralization of the Dayin’gezhuang gold deposit occurred at about 120 Ma.The ore-forming fluids were H_(2)O-CO_(2)-NaCl-type hydrothermal solutions with a medium-low temperature and medium-low salinity.The H-O isotopic characteristics indicate that the fluids in the early ore-forming stage were possibly magmatic water or mantle water and that meteoric water gradually entered the ore-forming fluids in the late ore-forming stage.The S and Pb isotopes indicate that the ore-forming materials mainly originate from the lower crust and contain a small quantity of mantle-derived components.The comprehensive analysis shows that the Dayin’gezhuang gold deposit was formed by thermal uplifting-extensional tectonism.The strong crust-mantle interactions,large-scale magmatism,and the material exchange arising from the transformation from adakitic granites to arc granites and from the ancient lower crust to the juvenile lower crust during the Early Cretaceous provided abundant fluids and material sources for mineralization.Moreover,the detachment faults formed by the rapid magmatic uplift and the extensional tectonism created favorable temperature and pressure conditions and space for f

关键词： Stepped metallogenic model Thermal uplifting-extension mineralization Geological characteristics Supergiant gold deposit Zhaoping metallogenic belt Jiaodong gold province Mineral exploration engineering Dayin’gezhuang Shandong Province China