LIVIVO - Search results -

Search results

Result 1 - 10 of total 111

Search options

Article ; Online: Sources and mean transit times of stream water in an intermittent river system

Z. Zhou / I. Cartwright / U. Morgenstern

Hydrology and Earth System Sciences, Vol 26, Pp 4497-

the upper Wimmera River, southeast Australia

2022 Volume 4513

Abstract: Determining the mean transit times (MTTs) and water sources in catchments at different flow conditions helps better understand river functioning, and manage river health and water resources. Despite being common in a range of environments, the MTTs and ... ...

Abstract	Determining the mean transit times (MTTs) and water sources in catchments at different flow conditions helps better understand river functioning, and manage river health and water resources. Despite being common in a range of environments, the MTTs and water sources in intermittent streams are much less well understood compared to perennial streams. Major ion geochemistry, stable isotopes, 14 C, and 3 H were used in this study to identify water sources and MTTs of the periodically intermittent upper Wimmera River from southeast Australia at different flow conditions, including zero-flow periods. The disconnected pool waters during the zero-flow period in the summer months of 2019 had 3 H activities of 0.64 to 3.29 TU. These and the variations in total dissolved solids and stable isotopes imply that these pools contained a mixture of older groundwater and younger stream water impacted by evaporation. 3 H activities during the high-flow period in July 2019 were 1.85 to 3.00 TU, yielding MTTs of up to 17 years. The 3 H activities at moderate and low-flow conditions in September and November 2019 ranged from 2.26 to 2.88 TU, implying MTTs of 1.6 to 7.8 years. Regional groundwater near the Wimmera River had 3 H activities of < 0.02 to 0.45 TU and 14 C activities of 57 to 103 pMC, and was not recharged by the river at high flows. The Wimmera River and other intermittent streams in southeast Australia are sustained by younger catchment waters from relatively small near-river stores than comparable perennial streams, which have older deeper regional groundwater inputs. This results in these intermittent streams being more susceptible to short-term changes in climate and necessitates the protection of near-river corridors to maintain the health of the riverine systems.
Keywords	Technology ; T ; Environmental technology. Sanitary engineering ; TD1-1066 ; Geography. Anthropology. Recreation ; G ; Environmental sciences ; GE1-350
Subject code	333 ; 550
Language	English
Publishing date	2022-09-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Analysis of the influence of environmental change on river runoff in Loess Plateau of China

Y. Jing / Z. Zhou

Proceedings of the International Association of Hydrological Sciences, Vol 383, Pp 111-

2020 Volume 119

Abstract: The double interaction between climate change and human activity affects the changes in the environmental conditions of catchment runoff and confluence. Using 1956–2012 57 years of river runoff series data of 27 rivers in hilly gully area of Loess ... ...

Abstract	The double interaction between climate change and human activity affects the changes in the environmental conditions of catchment runoff and confluence. Using 1956–2012 57 years of river runoff series data of 27 rivers in hilly gully area of Loess Plateau in Shaanxi province 39 hydrological station data, reduction of social and economic water consumption, plotting the annual precipitation and annual runoff double cumulative curve of annual runoff flow series consistency test, the consistency processing of annual runoff data and the quantitative analysis of its influence were also made. The results show that: the consistency of annual runoff data sequence of 21 hydrological stations is affected by the change of environmental conditions of runoff generation and confluence, and the turning point (year) and the degree of impact can be divided into three situations or three periods. One is the 12 station in 2000 after the annual runoff system is small; Two, there are 4 stations before and after in 1970, the annual precipitation and annual runoff double cumulative curve is obviously turning point. Before the turning point, a series of systems has a large high production period. After turning, it shows that a series of systems with low runoff yield caused by the Changes in environmental conditions of runoff and confluence in the underlying surface and climate and so on; the three is to have 5 stations occurred both before and after the 1970 high low flow period of the transition period in 2000, and after the annual runoff series of small low again.
Keywords	Environmental sciences ; GE1-350 ; Geology ; QE1-996.5
Subject code	550
Language	English
Publishing date	2020-09-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Effects of dynamic changes of desiccation cracks on preferential flow

Y. Luo / J. Zhang / Z. Zhou / J. P. Aguilar-Lopez / R. Greco / T. Bogaard

Hydrology and Earth System Sciences, Vol 27, Pp 783-

experimental investigation and numerical modeling

2023 Volume 808

Abstract: Preferential flow induced by desiccation cracks (PF-DC) has been proven to be an important hydrological effect that could cause various geotechnical engineering and ecological environment problems. Investigation on the PF-DC remains a great challenge due ...

Abstract	Preferential flow induced by desiccation cracks (PF-DC) has been proven to be an important hydrological effect that could cause various geotechnical engineering and ecological environment problems. Investigation on the PF-DC remains a great challenge due to the soil shrinking–swelling behavior. This work presents an experimental and numerical study of the PF-DC considering the dynamic changes of desiccation cracks. A soil column test was conducted under wetting–drying cycles to investigate the dynamic changes of desiccation cracks and their hydrological response. The ratios between the crack area and soil matrix area (crack ratio), crack aperture and depth were measured. The soil water content, matrix suction and water drainage were monitored. A new dynamic dual-permeability preferential flow model (DPMDy) was developed, which includes physically consistent functions in describing the variation of both porosity and hydraulic conductivity in crack and matrix domains. Its performance was compared to the single-domain model (SDM) and rigid dual-permeability model (DPM) with fixed crack ratio and hydraulic conductivity. The experimental results showed that the maximum crack ratio and aperture decreased when the evaporation intensity was excessively raised. The self-closure phenomenon of cracks and increased surficial water content was observed during low-evaporation periods. The simulation results showed that the matrix evaporation modeled by the DPMDy is lower than that of the SDM and DPM, but its crack evaporation is the highest. Compared to the DPM, the DPMDy simulated a faster pressure head building-up process in the crack domain and higher water exchange rates from the crack to the matrix domain during rainfall. Using a fixed crack ratio in the DPM, whether it is the maximum or the average value from the experiment data, will overestimate the infiltration fluxes of PF-DC but underestimate its contribution to the matrix domain. In conclusion, the DPMDy better described the underlying physics involving crack ...
Keywords	Technology ; T ; Environmental technology. Sanitary engineering ; TD1-1066 ; Geography. Anthropology. Recreation ; G ; Environmental sciences ; GE1-350
Subject code	669
Language	English
Publishing date	2023-02-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: F-region drift current and magnetic perturbation distribution by the X-wave heating ionosphere

Y. Li / H. Li / J. Wu / X. Lv / C. Yuan / C. Li / Z. Zhou

Annales Geophysicae, Vol 41, Pp 541-

2023 Volume 549

Abstract: We present a theoretical and numerical study of the drift current and magnetic perturbation model in the ionosphere by incorporating the ohmic heating model and the magnetohydrodynamic (MHD) momentum equation. Based on these equations, the ionospheric ... ...

Abstract	We present a theoretical and numerical study of the drift current and magnetic perturbation model in the ionosphere by incorporating the ohmic heating model and the magnetohydrodynamic (MHD) momentum equation. Based on these equations, the ionospheric electron temperature and drift current are investigated. The results indicate that the maximum change in electron temperature Δ T e is about 570 K, and the ratio is Δ T e / T e <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="89ed94e2716d485411679d449e71b6b0"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-41-541-2023-ie00001.svg" width="36pt" height="14pt" src="angeo-41-541-2023-ie00001.png"/></svg:svg> ∼ 48 %. The maximum drift current density is 8 × 10 - 10 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="46pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="fd33264e50dc5150a72b5fe5cda2ffba"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="angeo-41-541-2023-ie00002.svg" width="46pt" height="14pt" src="angeo-41-541-2023-ie00002.png"/></svg:svg> A m −2 , and its surface integral is 5.76 A. Diamagnetic drift current is the main form of current. The low collision frequency between charged particles and neutral particles has little effect on the current, and the collision frequency of electrons and ions is independent of the drift current. The current density profile is a flow ring. We present the effective conductivity as a function of the angle between the geomagnetic field and the radio wave; the model explains why the radiation efficiency was strongest when the X wave is heating along the magnetic dip angle, as reported in recent observations by Kotik et al. (2013). We calculate the magnetic field variation in the heating region based on the MHD theory: the results show that the maximum magnetic field perturbation in the heating area is 48 pT.
Keywords	Science ; Q ; Physics ; QC1-999 ; Geophysics. Cosmic physics ; QC801-809
Subject code	530
Language	English
Publishing date	2023-12-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: TIMP1 may affect goat prolificacy by regulating biological function of granulosa cells

L. Hong / X. Chen / M. Zhu / Z. Ao / W. Tang / Z. Zhou

Archives Animal Breeding, Vol 65, Pp 105-

2022 Volume 111

Abstract: Tissue inhibitor of metalloproteinase 1 (TIMP1) is associated with animal reproductive processes, such as follicular growth, ovulation, luteinization, and embryo development in mammals. The purposes of this study were to explore the expression and ... ...

Abstract	Tissue inhibitor of metalloproteinase 1 (TIMP1) is associated with animal reproductive processes, such as follicular growth, ovulation, luteinization, and embryo development in mammals. The purposes of this study were to explore the expression and localization of TIMP1 in the ovarian tissues and determine the effect of TIMP1 on the function of granulosa cells and the association of TIMP1 with lambing-related genes of the goats. Immunohistochemical analysis showed that TIMP1 protein was strongly expressed by granulosa cells. Enzyme-linked immunosorbent assay (ELISA) results showed that TIMP1 overexpression promoted the secretion of estradiol of granulosa cells after 12, 24, and 48 h of transfection. Moreover, in vitro experiments indicated that TIMP1 had the ability to promote the cell proliferation and elevate the transcriptional levels of four genes associated with goat prolificacy, including BMPR-1B , BMP15 , GDF9 , and FSHB , in granulosa cells. In conclusion, TIMP1 could be an important molecule in regulating reproductive performance of the goats by affecting estrogen secretion and cell proliferation, as well as the expression of lambing-related genes of granulosa cells in the goats.
Keywords	Agriculture ; S ; Animal culture ; SF1-1100 ; Science ; Q ; Zoology ; QL1-991
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Application of an improved distributed hydrological model based on the soil–gravel structure in the Niyang River basin, Qinghai–Tibet Plateau

P. Wang / Z. Zhou / J. Liu / C. Xu / K. Wang / Y. Liu / J. Li / Y. Li / Y. Jia / H. Wang

Hydrology and Earth System Sciences, Vol 27, Pp 2681-

2023 Volume 2701

Abstract: Runoff formation and hydrologic regulation mechanisms in mountainous cold regions are the basis for investigating the response patterns of hydrological processes under climate change. Because of plate movements and climatic effects, the surface soils of ... ...

Abstract	Runoff formation and hydrologic regulation mechanisms in mountainous cold regions are the basis for investigating the response patterns of hydrological processes under climate change. Because of plate movements and climatic effects, the surface soils of bare lands and grasslands on the Qinghai–Tibet Plateau (QTP) are thin, and the soil below the surface contains abundant gravel. This characteristic geological structure, combined with snow and frozen soil, affects the water cycle in this region. To investigate the influence of the underlying surface structure on water–heat transport and water circulation processes on the QTP, a comprehensive study was performed combining water–heat transfer field experiments, and a water and energy transfer process model for the QTP (WEP-QTP) was developed based on the original water and energy transfer process model in cold regions (WEP-COR). The Niyang River basin, located on the QTP, was selected as the study area to evaluate the consistency between theoretical hypotheses, observations, and modeling results. The model divided the uniform soil profile into a dualistic soil–gravel structure. When no phase change was present in the ground, two infiltration models based on the dualistic soil–gravel structure were developed; these used the Richards equation to model a non-heavy rain scenario and the multilayer Green–Ampt model for a heavy rain scenario. During the freeze–thaw period, a water–heat coupling model based on the snow–soil–gravel layer structure was constructed. By considering gravel, the improved model corrected the overestimation of the moisture content below the surface soil predicted by the original model and reduced the moisture content relative error (RE) from 33.74 % to − 12.11 %. The addition of the snow layer not only reduced the temperature fluctuation of the surface soil, but also revised the overestimation of the freeze–thaw speed predicted by the original model with the help of the gravel. The temperature root-mean-square error was reduced from 1.16 to 0.86 ...
Keywords	Technology ; T ; Environmental technology. Sanitary engineering ; TD1-1066 ; Geography. Anthropology. Recreation ; G ; Environmental sciences ; GE1-350
Subject code	550
Language	English
Publishing date	2023-07-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Water replenishment for ecological flow with E-WAS framework

Z. Yan / Z. Zhou / X. Sang / H. Wang / Y. Jia

Proceedings of the International Association of Hydrological Sciences, Vol 383, Pp 327-

a case study of the Longgang River Basin, Shenzhen, China

2020 Volume 339

Abstract: With rapid urbanization, there will be more conflict between human systems and the riverine ecological system, and therefore, ecological operations, practices and research must involve the ecological water replenishment of entire river basins with new ... ...

Abstract	With rapid urbanization, there will be more conflict between human systems and the riverine ecological system, and therefore, ecological operations, practices and research must involve the ecological water replenishment of entire river basins with new modeling tools. In this study, we establish an ecological flow-oriented water resource allocation and simulation framework (E-WAS). Virtual reservoirs and ecological units are added to the water resources network. With new water balance equations for virtual reservoirs and ecological units, the E-WAS can simulate the ecological replenishment process in a river basin and can provide a recommended water replenishment scheme that considers optimization principles. The E-WAS was applied in the Longgang River Basin, Shenzhen, China. 17 ecological units and 45 water supply nodes are considered in the model. A water replenishment scheme that used water from 31 reservoirs and reclaimed water from 7 water sewage plants was selected. This scheme significantly increased the satisfactory degree of ecological water demand and efficiently supported the formulation of a control scheme for the water environment of a basin. The E-WAS framework is similar to model plug-ins but helps to avoid the large workload that is required for model redevelopment and can expand the functions of models quickly.
Keywords	Environmental sciences ; GE1-350 ; Geology ; QE1-996.5
Subject code	550
Language	English
Publishing date	2020-09-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: A decagonal quasicrystal with rhombic and hexagonal tiles decorated with icosahedral structural units

W. Z. Wang / X. Z. Zhou / Z. Q. Yang / Y. Qi / H. Q. Ye

IUCrJ, Vol 7, Iss 3, Pp 535-

2020 Volume 541

Abstract: The structure of a decagonal quasicrystal in the Zn58Mg40Y2 (at.%) alloy was studied using electron diffraction and atomic resolution Z-contrast imaging techniques. This stable Frank–Kasper Zn–Mg–Y decagonal quasicrystal has an atomic structure which can ...

Abstract	The structure of a decagonal quasicrystal in the Zn58Mg40Y2 (at.%) alloy was studied using electron diffraction and atomic resolution Z-contrast imaging techniques. This stable Frank–Kasper Zn–Mg–Y decagonal quasicrystal has an atomic structure which can be modeled with a rhombic/hexagonal tiling decorated with icosahedral units at each vertex. No perfect decagonal clusters were observed in the Zn–Mg–Y decagonal quasicrystal, which differs from the Zn–Mg–Dy decagonal crystal with the same space group P10/mmm. Y atoms occupy the center of `dented decagon' motifs consisting of three fat rhombic and two flattened hexagonal tiles. About 75% of fat rhombic tiles are arranged in groups of five forming star motifs, while the others connect with each other in a `zigzag' configuration. This decagonal quasicrystal has a composition of Zn68.3Mg29.1Y2.6 (at.%) with a valence electron concentration (e/a) of about 2.03, which is in accord with the Hume–Rothery criterion for the formation of the Zn-based quasicrystal phase (e/a = 2.0–2.15).
Keywords	decagonal quasicrystals ; icosahedrons ; penrose tiling ; electron diffraction ; scanning-transmission electron microscopy ; Science ; Q
Subject code	669
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	International Union of Crystallography
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Stratification observed by the in situ plasma density measurements from the Swarm satellites

X. Wang / W. Cheng / Z. Zhou / D. Yang / J. Cui / F. Guo

Annales Geophysicae, Vol 38, Pp 517-

2020 Volume 526

Abstract: The stratification phenomenon is investigated using the simultaneous in situ plasma density measurements obtained by the Swarm satellites orbiting at different altitudes above the F2 peak. For the first time, the continuous distribution morphology and ... ...

Abstract	The stratification phenomenon is investigated using the simultaneous in situ plasma density measurements obtained by the Swarm satellites orbiting at different altitudes above the F2 peak. For the first time, the continuous distribution morphology and the exact locations are obtained for the nighttime stratification, which show that the stratification events are centered at the EIA (equatorial ionization anomaly) trough and extend towards the two EIA crests, with the most significant part being located at the EIA trough. Another new discovery is the stratification in southern mid-latitudes; stratification events in this region are located on a local plasma peak sandwiched by two lower density strips covering all the longitudes. The formation mechanism of the stratification for the two latitudinal regions is discussed, but the stratification mechanism in southern mid-latitudes remains an unsolved problem. Highlights. This paper addresses the following: first application of in situ plasma densities for the direct analysis of the stratification in F2 layer, refined features of the exact location and continuous morphology for the stratification phenomenon, a new discovery of stratification covering all longitudes in southern mid-latitudes.
Keywords	Science ; Q ; Physics ; QC1-999 ; Geophysics. Cosmic physics ; QC801-809
Subject code	551
Language	English
Publishing date	2020-04-01T00:00:00Z
Publisher	Copernicus Publications
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Burden of respiratory infections and otitis media in the Inuit population of Nunavik, Quebec, Canada

Philippe De Wals / Z Zhou / J. B. LeMeur / J. F. Proulx

International Journal of Circumpolar Health, Vol 79, Iss

2020 Volume 1

Abstract: Background Respiratory infections are a major health problem in the Inuit population of Nunavik, province of Quebec, Canada. Objectives A study was undertaken to assess the burden of lower (LRTI) and upper respiratory tract infections (URTI) and otitis ... ...

Abstract	Background Respiratory infections are a major health problem in the Inuit population of Nunavik, province of Quebec, Canada. Objectives A study was undertaken to assess the burden of lower (LRTI) and upper respiratory tract infections (URTI) and otitis media (OM) and to explore some of their determinants including the pneumococcal conjugate vaccine (PCV) status. Methods The reference population includes children less than 5 years of age born in 1994–2010 and a sample of 825 children was selected for this study. Outpatient medical records were reviewed. Visits with a diagnosis of LRTI, URTI and OM were extracted. Univariate and multivariate statistical analyses were performed to identify predictors of disease risk. Results The average number of LRTI, URTI and OM episodes were, respectively, 2.6, 6.2 and 5.9 from birth up to the 5th birthday. Seasonal patterns were similar for URTI and OM, but was different for LRTI. Children who received the recommended 4 PCV doses had a lower LRTI and OM risk than unvaccinated children. There was a trend towards a lower OM risk associated with a mixed PCV10+ PCV13 schedule compared with PCV7. Conclusion Results suggest a lower LRTI and OM risk associated with PCV use in this high-risk population but respiratory disease risk remains high compared with the general population in Quebec.
Keywords	pneumococcal conjugate vaccines ; respiratory infections ; otitis media ; outpatient visits ; Arctic medicine. Tropical medicine ; RC955-962
Subject code	610
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	Taylor & Francis Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED