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Impacts of Water-Sediment Regulation Scheme on Chromophoric Dissolved Organic Matter in the Lower Yellow River
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作者 LIU Xiao JIANG Xueyan +2 位作者 LIU Qian SUI Juanjuan ZOU Li 《Journal of Ocean University of China》 CAS CSCD 2024年第2期455-466,共12页
As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water quality.Water-sediment regulation scheme(WSRS),which has been c... As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water quality.Water-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water quality.Chromophoric dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human activities.Here,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during WSRS.In addition,a parallel factor fluorescence analysis(PARAFAC)method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3)and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3 increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM compositions.Under the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS period.Sediment resuspension inhibits microbial activities and reduces the production of autochthonous CDOM.Overall,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment. 展开更多
关键词 chromophoric dissolved organic matter(CDOM) water-sediment regulation scheme(WSRS) Yellow River optical properties
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Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China 被引量:1
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作者 Jin Hu HaiBing Ruan +2 位作者 FuQing Huang ShengYang Gu XianKang Dou 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期400-407,共8页
The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G... The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions. 展开更多
关键词 International GNSS Service(IGS)Global Ionosphere Maps(GIM) Crustal movement Observation Network of China(CMONOC) total electron content(TEC) data assessment
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Modifying the progression of Parkinson's disease through movement interventions:multimodal quantification of underlying mechanisms
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作者 Manuel Bange Damian Marc Herz +2 位作者 Dumitru Ciolac Gabriel Gonzalez-Escamilla Sergiu Groppa 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第8期1651-1652,共2页
Introduction:Parkinson’s disease(PD)is the most common neurodegenerative movement disorder.The pathological hallmark is the progressive loss of dopaminergic neurons of the substantia nigra pars compacta,which is acco... Introduction:Parkinson’s disease(PD)is the most common neurodegenerative movement disorder.The pathological hallmark is the progressive loss of dopaminergic neurons of the substantia nigra pars compacta,which is accompanied by widespread alterations in the structu re and function of distributed brain networks.Togethe r,these processes cause a variety of motor symptoms such as bradykinesia,rigidity,tremor,gait disorders,or difficulties in fine motor control(Bange et al.,2022). 展开更多
关键词 alterations movement
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Dual roles of the amygdala-hippocampus circuit in the regulation of rapid eye movement sleep and depression symptoms by repetitive transcranial magnetic stimulation in patients with insomnia
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作者 Xiaoyang Liu Xumeng Zhao +7 位作者 Ziqiang Shao Yongjian Guo Lirong Yue Jiayi Liu Dahua Yu Xiaona Sheng Yifei Zhu Kai Yuan 《General Psychiatry》 CSCD 2024年第2期297-300,共4页
To the editor:It is commonly reported that people with insomnia often experience comorbid emotional disorders,such as mood and anxiety disorders.12 A study found that fragmented rapid eye movement(REM)sleep in individ... To the editor:It is commonly reported that people with insomnia often experience comorbid emotional disorders,such as mood and anxiety disorders.12 A study found that fragmented rapid eye movement(REM)sleep in individuals with insomnia is associated with higher Beck Depression Inventory(BDI)scores.3 REM sleep architecture disruption is a typical symptom of insomnia. 展开更多
关键词 SLEEP STIMULATION movement
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Present-day movement characteristics of the Qinghai Nanshan fault and its surrounding area from GPS observation
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作者 Yang Liu Yuxuan Qiu +5 位作者 Jialiang Liu Luyun Xiong Caijun Xu Jianghui Geng Gang Zheng Tianchen Sheng 《Geodesy and Geodynamics》 EI CSCD 2024年第2期133-141,共9页
The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau.In previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transfo... The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau.In previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transformation role of the fault on its east is not yet clear.This study uses data fusion to obtain denser GPS observations near the Qinghai Nanshan fault.Based on tectonic characteristics,we establish a block model to investigate the fault slip rate,locking degree,and slip deficit.The results show that the Qinghai Nanshan fault slip rate is characterized by sinistral and convergent movement.Both the sinistral and convergent rates display a decreasing trend from west to east.The locking degree and slip deficit are higher in the western segment(with an average of about 0.74 and 1.1 mm/a)and lower in the eastern segment.Then,we construct a strain rate field using GPS observations to analyze the regional strain characteristics.The results indicate that along the fault,the western segment shows a larger shear strain rate and negative dilation rate.Regional earthquake records show that the frequency of earthquakes is lower near the fault.The joint results suggest that the western segment may have a higher earthquake risk.In addition,the insignificant fault slip rate in the eastern segment may indicate that it does not participate in the tectonic transformation among the Riyueshan,Lajishan,and West Qinling faults. 展开更多
关键词 The Qinghai Nanshan fault movement characteristics Block model Slip rate GPS
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Obtaining 2D Soil Geotechnical Profiles from Cokriging Interpolation of Sample Data and Electrical Resistivity Tomography (ERT)—Applications in Mass Movements Studies
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作者 Cassiano Antonio Bortolozo Noel Howley +11 位作者 Andy Legg Tristan Pryer Danielle Silva de Paula Tatiana Sussel Gonçalves Mendes Daniel Metodiev Marcio Roberto Magalhães de Andrade Silvio Jorge Coelho Simões Maiconn Vinicius de Moraes Marcio Augusto Ernesto de Moraes Luana Albertani Pampuch Rodolfo Moreda Mendes Harideva Marturano Egas 《International Journal of Geosciences》 CAS 2024年第7期525-548,共24页
Brazil annually faces significant challenges with mass movements, particularly in areas with poorly constructed housing, inadequate engineering, and lacking sanitation infrastructure. Campos do Jordão, in Sã... Brazil annually faces significant challenges with mass movements, particularly in areas with poorly constructed housing, inadequate engineering, and lacking sanitation infrastructure. Campos do Jordão, in São Paulo state, is a city currently grappling with these issues. This paper details a study conducted within a pilot area in Campos do Jordão, where geophysical surveys and geotechnical borehole data were integrated. The geophysical surveys provided 2D profiles, and samples were collected to analyse soil moisture and plasticity. These datasets were combined using a Cokriging-based model to produce an accurate representation of the subsurface conditions. The enhanced modelling of subsurface variability facilitates a deeper understanding of soil behavior, which can be used to improve landslide risk assessments. This approach is innovative, particularly within the international context where similar studies often do not address the complexities associated with urban planning deficits such as those observed in some areas of Brazil. These conditions, including the lack of proper sanitation and irregular housing, significantly influence the geological stability of the region, adding layers of complexity to subsurface assessments. Adapting geotechnical evaluation methods to local challenges offers the potential to increase the efficacy and relevance of geological risk management in regions with similar socio-economic and urban characteristics. 展开更多
关键词 Mass movements GEOPHYSICS ERT Geotechnical Surveys Campos do Jordão COKRIGING
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Effect of different interventions on orthodontic tooth movement acceleration:A network meta-analysis
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作者 CHEN Hui-ying ZHANG Li +2 位作者 ZHAN Le WAN Ni MO Li-wen 《Journal of Hainan Medical University》 CAS 2024年第2期41-50,共10页
Objective: To explore the effectiveness of various interventions in accelerating tooth movement, a systematic review and net-work meta analysis were used to draw a conclusion. Methods: MEDLINE, EMBASE, Willey Library,... Objective: To explore the effectiveness of various interventions in accelerating tooth movement, a systematic review and net-work meta analysis were used to draw a conclusion. Methods: MEDLINE, EMBASE, Willey Library, EBSCO, Web of Science Databases, and Cochrane Central Register of Controlled Trials databases to identify relevant studies. ADDIS 1.16.6 and Stata 16.0 software were used for NMA. Results: Five thousand five hundred and forty-two articles were searched out. After screening by two independent investigators, forty-seven randomized controlled trials, 1 390 participants, were included in this network meta-analysis. A total of 11 interventions involving Piezocision (Piezo), Photobiomodulation therapy (PBMT), Plate- let-rich plasma(PRP), Electromagnetic field(EF), Low intensity laser therapy(LLLT), Low intensity pulsed ultrasound(LI-PUS), Low-frequency vibrations(LFV), Distraction osteogenesis(DAD), Corticotomy(Corti), Microosteoperforations (MOPS), Traditional orthodontic(OT)were identified and classified into 3 classes including surgical treatment, non-surgical treatment and traditional orthodontic treatment. According to SUCRA probability ranking of the best intervention effect, when orthodontic treatment lasted for 1 month, PBMT (90.6%), Piezo(87.4%) and MOPs(73.6%)were the top three interventions to improve the efficiency of canine tooth movement. When orthodontic treatment lasted for 2 months, Corti (75.7%), Piezo (69.6%) and LFV(58.9%)were the top three interventions for improving the mobility efficiency of canine tooth movement. When orthodontic treatment lasted for 3 months, Cort (73.3%), LLLT(68.4%)and LFV(60.8%)were the top three interventions for improving the mobility efficiency of canine tooth movement. Conclusion: PBMT and Piezo can improve the efficiency of canine tooth movement significantly after 1 month, while Corti and LFV can improve the efficiency of canine tooth movement better after 2 and 3 months. 展开更多
关键词 Orthodontic tooth movement ACCELERATION Network Meta-analysis Randomized controlled trials
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Association between Meeting 24-Hour Movement Guidelines and Psychological Features of Chinese Emerging Adults
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作者 Yanjie Zhang Jin Kuang +2 位作者 Xun Luo Mengxian Zhao Xiaolei Liu 《International Journal of Mental Health Promotion》 2024年第5期399-406,共8页
Background:Emerging adulthood is a pivotal life stage,presenting significant psychological and social changes,such as decreased sociability,depression,and other mental health problems.Previous studies have associated ... Background:Emerging adulthood is a pivotal life stage,presenting significant psychological and social changes,such as decreased sociability,depression,and other mental health problems.Previous studies have associated these changes with an unhealthy lifestyle.The 24-h movement guidelines for healthy lifestyles have been developed to promote appropriate health behaviors and improve individual wellness.However,the relationship between adherence to the 24-h movement guidelines and different characteristics of Chinese emerging adults is yet to be explored.This cross-sectional study aimed to investigate the association between adherence to the 24-h movement guidelines and four characteristics(self-exploration,instability,possibilities,and responsibility)of Chinese emerging adults.Methods:Overall,1,510 Chinese emerging adults aged 18–29 years were included in this study.Each participant completed a self-administered questionnaire that included questions on adherence to the 24-h movement guidelines(physical activity,sedentary behavior,and sleep)and the inventory of dimensions of emerging adulthood.Multivariable logistic regression analysis was employed to investigate the associations between adherence to the 24-h movement guidelines and each of the four characteristics.Results:The proportion of participants who adhered to the 24-h movement guidelines was 31.72%.Multiple regression analysis revealed a significantly negative relationship between adhering to more guidelines and instability(β=−0.51,p<0.001).A statistically significant association was observed between instability and meeting only sedentary behavior(β=−1.27,95%confidence interval[CI]:[−2.32,−0.24],p=0.02),sedentary behavior+sleep(β=−1.30,95%CI:[−2.24,−0.35],p<0.01),and physical activity+sedentary behavior(β=−1.08,95%CI:[1.94,−0.21],p=0.02)guidelines.Further,positive and significant associations were observed between possibilities and meeting the guidelines for only physical activity(β=0.70,95%CI:[0.14,1.27),p=0.01),only sleep(β=0.61,95%CI:[0.01,1.21],p=0.04),physical activity+sedentary behavior(β=0.56,95%CI:[0.04,1.07),p=0.01),and physical activity+sleep(β=0.76,95%CI:[0.23,1.27],p=0.01).Conclusions:These findings suggest that adherence to the 24-h movement guidelines was associated with instability in Chinese emerging adults.Future studies are warranted to verify our findings to highlight the importance of maintaining a heath lifestyle to promote health in emerging adulthood. 展开更多
关键词 24-h movement behavior physical activity sedentary behavior SLEEP psychological health emerging adults
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Movement Function Assessment Based on Human Pose Estimation from Multi-View
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作者 Lingling Chen Tong Liu +1 位作者 Zhuo Gong Ding Wang 《Computer Systems Science & Engineering》 2024年第2期321-339,共19页
Human pose estimation is a basic and critical task in the field of computer vision that involves determining the position(or spatial coordinates)of the joints of the human body in a given image or video.It is widely u... Human pose estimation is a basic and critical task in the field of computer vision that involves determining the position(or spatial coordinates)of the joints of the human body in a given image or video.It is widely used in motion analysis,medical evaluation,and behavior monitoring.In this paper,the authors propose a method for multi-view human pose estimation.Two image sensors were placed orthogonally with respect to each other to capture the pose of the subject as they moved,and this yielded accurate and comprehensive results of three-dimensional(3D)motion reconstruction that helped capture their multi-directional poses.Following this,we propose a method based on 3D pose estimation to assess the similarity of the features of motion of patients with motor dysfunction by comparing differences between their range of motion and that of normal subjects.We converted these differences into Fugl–Meyer assessment(FMA)scores in order to quantify them.Finally,we implemented the proposed method in the Unity framework,and built a Virtual Reality platform that provides users with human–computer interaction to make the task more enjoyable for them and ensure their active participation in the assessment process.The goal is to provide a suitable means of assessing movement disorders without requiring the immediate supervision of a physician. 展开更多
关键词 Human pose estimation 3D pose reconstruction assessment of movement function plane of features of human motion
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Muscle Strength, Lumbar Curve, Fear of Movement and Functional Disability among Patients with Lumbar Disc Herniation: A Review
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作者 G. M. Jakaria Chua Siew Kuan 《Open Journal of Therapy and Rehabilitation》 2024年第1期28-51,共24页
Introduction: Lumbar disc herniation (LDH) refers to the rupture of the fibrous annulus of the intervertebral discs. Lumbar curvature may lead to the occurrence of lumbar disc degeneration. Fear of movement may worsen... Introduction: Lumbar disc herniation (LDH) refers to the rupture of the fibrous annulus of the intervertebral discs. Lumbar curvature may lead to the occurrence of lumbar disc degeneration. Fear of movement may worsen their disc herniation and cause further pain and injury. LDH conditions impact the individuals’ quality of life, to explore the relationship between lumbar curve, muscle strength, fear of movement and functional disability among patients with LDH. Methods: An electronic search was conducted on PubMed, Medline, Science Direct, Springerlink, Google Scholar and a hand search from reference lists was reviewed. Publications were included in human studies, patients 25 - 85 years of age, original studies and published in English language journals from January 2002 to December 2023. Result: In total, 64 articles were researched through the online search engines, and 9 papers were found through manual searches of reference lists. As a result, a total of 11 articles were included for the purpose of this review. The comprehensive analysis revealed the presence of eight cross-sectional studies, two retrospective studies and one experimental study. A minimum of 25 participants and a maximum of 360 participants were included. Ten studies included both genders, only one studies included healthy adults and patients with LDH but these studies didn’t mention gender. Results showed that the factors influencing LDH can be categorized into non-modifiable factors, such as gender, age, height or others. Modifiable factors included increased BMI, DM, smoking, alcohol, employment status, lifestyle and health problems or psychology. Conclusion: Females with greater VASC may be at risk of LDH. The lumbar extensor muscles indicated a localized disc herniation or nerve root pathology in patients with LDH. The fear of movement may lead to psychological consequences and reduce functional disability among patients with LDH. 展开更多
关键词 Lumbar Disc Herniation Fear of movement Functional Disability Vertical Angle of Spinal Curvature
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“Eternal Motion” as a “Form of Movement of a Special Nature” and the Main Condition for the Creation of the Universe
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作者 Avas Khugaev Eugeniya Bibaeva 《Journal of Applied Mathematics and Physics》 2024年第6期2041-2068,共28页
The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-su... The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-sufficiency, and by “Special Nature”, gravitational and two other properties of matter, “tied” to the “Eternal Movement” and completely dependent on it. Carriers of key properties of a “Special Nature” have been established: “0”-DE particles and “3”-DM particles (UDM). The unity of their inherent “motionally-gravitational” properties and the peculiarity of the relationship between “motion” and “gravity” are revealed: the higher the intensity of “Eternal Motion”, the stronger the gravitational properties of matter are manifested (and vice versa). The relationship of “time” with the “vibration frequency” and the “mass” of photons with the “degree of bonding and deformation properties of the field” is shown. The maximum level of gravity has been determined, which allows Nature to successfully create the Universe: such a landmark is the proximity to the property of the Primary Source—the “pure graviton” of the OSP space, the most powerful “motionally-gravitational” particle of the Universe. The reasons for the emergence of such an identity of the gravitational properties of particles with the indicators of a “pure graviton” are established: for “0”-DE particles, this is the acquisition of the function of “freedom of movement”;for “3”-DM particles (UDM), the creation of a special structure—a “double field” (“Main” and “Small”). The presence in the “double field” of specific “tools” for the creation of the worlds of the Universe—gravitational “waves” gives rise to impulses (shocks) of varying intensity and shape. A list of functions performed by “waves” in the “Main” and “Small” fields has been compiled. The specific conditions for the formation of “UDM Streams”, their transformation into a “Vortex” and, under the influence of a powerful Initial Impulse (push), sending them to the “place” of the creation of galaxies, are shown. It is suggested that there is a “Cycle of Matter in Nature” in the closed structure of our Universe due to the “work” of “waves” and the functioning of special “factories” in the form of exotic space objects—Black holes. 展开更多
关键词 DE DM (UCM) Graviton Eternal motion Double Field of the Universe Motionally-Gravitational Particles Degree of Self-Sufficiency Main Field Small Field Gravitational Waves Primary Impulse Flows UDM Vortex Time Massive Photons Clumps of DM movement of Galaxies Factories of Black Holes Circulation of Matter in Nature
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Effect of water-sediment regulation and its impact on coastline and suspended sediment concentration in Yellow River Estuary 被引量:7
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作者 Hai-bo Yang En-chong Li +1 位作者 Yong Zhao Qiu-hua Liang 《Water Science and Engineering》 EI CAS CSCD 2017年第4期311-319,共9页
Implementation of the water-sediment regulation(WSR) scheme, mainly focused on solving the sedimentation problems of reservoirs and the lower reaches of the Yellow River, has inevitably influenced the sediment distrib... Implementation of the water-sediment regulation(WSR) scheme, mainly focused on solving the sedimentation problems of reservoirs and the lower reaches of the Yellow River, has inevitably influenced the sediment distribution and coastal morphology of the Yellow River Estuary.Using coastline delineation and suspended sediment concentration(SSC) retrieval methods, this study investigated water and sediment changes,identified detailed inter-annual and intra-annual variations of the coastline and SSC in the normal period(NP: 1986-2001, before and after the flood season) and WSR period(WSRP: 2002-2013, before and after WSR). The results indicate that(1) the sedimentation in the low reaches of the Yellow River turned into erosion from 2002 onward;(2) the inter-annual coastline changes could be divided into an accretion stage(1986-1996), a slow erosion stage(1996-2002), and a slow accretion stage(2002-2013);(3) an intra-annual coastline extension occurred in the river mouth in most years of the WSRP; and(4) the mean intra-annual accretion area was 0.789 km^2 in the NP and 4.73 km2 in the WSRP,and the mean SSC increased from 238 mg/L to 293 mg/L in the NP and from 192 mg/L to 264 mg/L in the WSRP. 展开更多
关键词 COASTLINE Suspended SEDIMENT concentration water-sediment REGULATION REMOTE sensing YELLOW River ESTUARY
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The influence of water-sediment regulation on macrobenthic community structures in the Huanghe River(Yellow River)Estuary during 2012–2016 被引量:2
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作者 Shaowen Li Fan Li +1 位作者 Xiukai Song Mingliang Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第10期120-128,共9页
To determine if water-sediment regulation has affected macrobenthic community structure in the Huanghe River Estuary,China,macrobenthic samples were collected following regulation events from 2012 to 2016.We identify ... To determine if water-sediment regulation has affected macrobenthic community structure in the Huanghe River Estuary,China,macrobenthic samples were collected following regulation events from 2012 to 2016.We identify seven phyla and 138 macrobenthic species from within samples throughout the survey area,over time.Species richness and abundance in 2012 were significantly higher than in 2016.Biomass did not differ significantly during 2012–2016.Dominant species were mostly small polychaetes,with mollusks,arthropods,and echinoderms all being relatively rare.In 2016,dominant species were small polychaetes.MDS reveals macrobenthic communities at all surveyed distances from the estuary to have become the same community structure over time.Shannon-Wiener diversity and Margalef richness indexes trended down over time.CCA reveals the most dominant sediment-dwelling species to prefer lower dissolved oxygen,sulfides,and pH,and sediments with high D50 and low clay content.We speculate that water-sediment regulation has affected seabed communities,particularly Region A in our survey area. 展开更多
关键词 Huanghe River Estuary MACROBENTHOS water-sediment regulation community structure
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Nutrient exchange and release experiment and its simulation study in lake water-sediment interface 被引量:1
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作者 XUE Lian-qing HAO Zhen-chun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第3期591-595,共5页
The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate a... The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate and assess the influence degree to lake water quality. Based on the dynamic water exchanging experiments the nutrient release process in sediment and influence mechanism to substance exchanging on water-sediment interface was studied, and the correlation between the changing content of total phosphors and total nitrogen in sediment and covered water were analyzed for setting up a simulation model. At the same time the influence degree is explained in detail. The experimental results indicated that even if clean water without nutrient contents was used for water exchangement so as to decrease pollution or prevent eutrophication, however owing to the vertical nutrient distribution in lake sediment, it will lead to the increasing release amount greatly especially when the organic nutrient contained in sediment turns into inorganic status because of isolation. Besides the release process of total phosphate (TP) and total nitrogen (TN) were modeled and each nutrient's exchanging equation at interface caused by covered water nutrient concentration changing was set up. According to the simulating prediction, TP and TN content of cover water will also sustain a steady higher level in a long period. The nutrient release amount of sediment is not only affected by the covered water concentration but also connects with accumulative time. The experiments provide the fundamental theoretical and practical basis for taking ecological restoration project. And research is helpful to prevent or restore lake eutrophication. 展开更多
关键词 phosphate and nitrogen release water-sediment interface experiments simulation model
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Impact of Water-Sediment Regulation on Variations of Amino Acids in the Middle-Lower Yellow River, China 被引量:1
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作者 ZHANG Kun ZOU Li +3 位作者 DAI Qunying WANG Jian JIANG Xueyan LIANG Shengkang 《Journal of Ocean University of China》 SCIE CAS CSCD 2020年第2期369-376,共8页
In order to examine the impacts of water-sediment regulation on regional carbon cycling,we collected water,particulate and sediment samples from the middle-lower Yellow River in late June and early July,2015 and analy... In order to examine the impacts of water-sediment regulation on regional carbon cycling,we collected water,particulate and sediment samples from the middle-lower Yellow River in late June and early July,2015 and analyzed their specific amino acids(AA),DOC,POC,and bacteria abundance.Summarized by 14 specific AA,the total hydrolysable AA(THAA),particulate AA(PAA),and sediment AA(SAA)varied in ranges of 2.29-9.05μmol L^-1,5.22-22.96μmol L^-1,and 81.7-137.19μg g^-1 dry weight.After the regulation,dissolved free AA(DFAA)decreased by 29%while DCAA increased by 72%.These variations suggested that DFAA were further degraded,while DCAA molecules were further activated.Meanwhile,PAA increased almost 4 times as many as those before regulation,and SAA increased as well.After regulation,the amounts of bioactive amino acids(Asp,Glu and Gly)increased in THAA but decreased in PAA,with little changes in SAA.The ratios of Asp/Gly in different phases increased after regulation,indicating the AA contributions were promoted by calcareous organisms rather than by siliceous organisms.Multiple correlation analysis showed that PAA was primary representatives of AA and organic carbon,followed by DCAA and POC.Moreover,bacterial reproduction played a key role in shaping the AA compositions and properties,followed by the redox condition and acid-base balance.The results of this study provided a clear evidence for the effects of water-sediment regulation on regional biogeochemistry of organic carbon in the middle-lower Yellow River. 展开更多
关键词 the middle-lower Yellow River water-sediment regulation amino acids organic carbon
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Determination of optimal grid opening width for herringbone water-sediment separation structures based on sediment separation efficiency 被引量:1
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作者 XIE Xiang-ping WEI Fang-qiang +1 位作者 WANG Xiao-jun YANG Hong-juan 《Journal of Mountain Science》 SCIE CSCD 2019年第3期619-629,共11页
The herringbone water-sediment separation structure(HWSSS) was developed to prevent debris flows. This paper mainly focuses on evaluating the sediment separation efficiency of HWSSS in debris flow prevention and deter... The herringbone water-sediment separation structure(HWSSS) was developed to prevent debris flows. This paper mainly focuses on evaluating the sediment separation efficiency of HWSSS in debris flow prevention and determining the grid opening width D, a crucial structure parameter for HWSSS design. Theoretical analysis on the total sediment separation rate Pt reveals that the efficiency of sediment separation is much related with sediment grain size distribution(GSD) and grid opening width. The lower limit of Pt is deduced from the perspective of safety consideration by transforming debris flow into sediment-laden flow. Hydraulic model tests were carried out. Based on the regression analysis of the experimental data, the quantitative relationships between Pt and D and GSD characteristic values were finally established. A procedure for determining optimal grid opening width is proposed based on these analyses. These results are of significance in evaluating sediment separation effect by HWSSS in debris flow prevention and contribute to a more explicit methodology for design of HWSSS. 展开更多
关键词 Debris flow water-sediment SEPARATION Structure design SEDIMENT SEPARATION efficiency GRID OPENING WIDTH
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THE STUDY ON THREE-DIMENSIONAL MATHEMATICAL MODEL OF RIVER BED EROSION FOR WATER-SEDIMENT TWO-PHASE FLOW 被引量:1
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作者 方红卫 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1996年第1期85-91,共7页
Based on the tensor analysis of water-sediment two-phase how, the basic model equations for clear water flow and sediment-laden flow are deduced in the general curve coordinates for natural water variable-density turb... Based on the tensor analysis of water-sediment two-phase how, the basic model equations for clear water flow and sediment-laden flow are deduced in the general curve coordinates for natural water variable-density turbulent how. Furthermore, corresponding boundary conditions are also presented in connection with the composition and movement of non-uniform bed material. The theoretical results are applied to the calculation of the float open caisson in the construction period and good results are obtained. 展开更多
关键词 flow mathematical model sediment-laden flow mathematical model water-sediment two-phase flow float open caisson
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Environmental Flow Assessment Using Water-Sediment Approach at the Sekampung River, Indonesia
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作者 Endro Prasetyo Wahono Djoko Legono +1 位作者   Istiarto Bambang Yulistiyanto 《Open Journal of Modern Hydrology》 2014年第4期164-172,共9页
Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for hum... Environmental issue has been considered more significant in many aspects of engineering decision-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for human use as well as nature, therefore environmental flow assessment has been widely developed. This paper discusses on environmental flow assessment of the Sekampung River, particularly on its middle reach. A new analytical approach based on water-sediment equations was introduced in order to determine a minimum environmental flow at the certain cross section of a river. The result of the new method was then compared with a minimum environmental flow provided by using two hydrological based methods, namely, Tennant and Flow Duration Curve Analysis (FDCA) method. The result shows that the concerned discharge provided by the water-sediment method (3.5 m3/s) is the smallest compare with a minimum environmental flow that is provided by both Tennant (5.7 m3/s) and FDCA method (4.5 m3/s). It is promising that the water-sediment method can be used as a simple approach on preliminary state of environmental flow assessment. The method involves not only water discharge but also its related sediment flow of the river in order to mitigate further ecological and morphological risks. 展开更多
关键词 water-sediment ENVIRONMENTAL FLOW RIVER MORPHOLOGY
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REE distribution in water-sediment interface system at deep ocean floor
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作者 Zhang Lijie Liu Jihua and Yao De ( Institute of Marine Geology, MGMR, Qingdao 266071, China) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1994年第4期519-526,共8页
REE concentrations and distribution patterns in the different phases of water-sediment interface system at deep ocean floor were studied on the basis of samples of bottom water, sediments, interstitial water and polym... REE concentrations and distribution patterns in the different phases of water-sediment interface system at deep ocean floor were studied on the basis of samples of bottom water, sediments, interstitial water and polymetallic nodules collected from the East Pacific Basin by R/V Haiyang 4 during HY4-871 and HY4-881Cruises. It is suggested that REE concentrations in oxic interstitial water are lower than that in bottom weter,REE contents of polymetallic nodules, except Ce, are similar to that of sediments. Bottom water, sediments and interstitial water are almost the same in REE distribution patterns. MREE enrichment relative to LREE and HREE and negative Ce anomalies, MREE earichment has been found in polymetallic nodules,and Ce shows positive anomalies. REE contents in sediments increase with depth, and the vacations of distribution patterns with depth have not been found. 展开更多
关键词 The East Pacific Basin water-sediment inter face system interstitial water rare earth elements
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Adaptive navigation assistance based on eye movement features in virtual reality 被引量:1
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作者 Song ZHAO Shiwei CHENG 《Virtual Reality & Intelligent Hardware》 2023年第3期232-248,共17页
Background Navigation assistance is essential for users when roaming virtual reality scenes;however,the traditional navigation method requires users to manually request a map for viewing,which leads to low immersion a... Background Navigation assistance is essential for users when roaming virtual reality scenes;however,the traditional navigation method requires users to manually request a map for viewing,which leads to low immersion and poor user experience.Methods To address this issue,we first collected data on who required navigation assistance in a virtual reality environment,including various eye movement features,such as gaze fixation,pupil size,and gaze angle.Subsequently,we used the boosting-based XGBoost algorithm to train a prediction model and finally used it to predict whether users require navigation assistance in a roaming task.Results After evaluating the performance of the model,the accuracy,precision,recall,and F1-score of our model reached approximately 95%.In addition,by applying the model to a virtual reality scene,an adaptive navigation assistance system based on the real-time eye movement data of the user was implemented.Conclusions Compared with traditional navigation assistance methods,our new adaptive navigation assistance method could enable the user to be more immersive and effective while roaming in a virtual reality(VR)environment. 展开更多
关键词 Eye movement NAVIGATION Human-computer interaction Virtual reality Eye tracking
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