The research progress of water-salt mechanism and migration model

2015 ◽  
pp. 369-372
Author(s):  
Guang-li Zhu ◽  
Long Zhu ◽  
Chao Yu
Keyword(s):  
Research Progress ◽  
Migration Model ◽  
Water Salt ◽  
And Migration

scholarly journals Mechanism and Influencing Factors of REY Enrichment in Deep-Sea Sediments

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 196
Author(s):  
Jiangbo Ren ◽  
Yan Liu ◽  
Fenlian Wang ◽  
Gaowen He ◽  
Xiguang Deng ◽  
...  
Keyword(s):  
Deep Sea ◽  
Research Progress ◽  
Bottom Current ◽  
Knowledge Map ◽  
P2o5 Content ◽  
Deep Sea Sediments ◽  
Potential Resource ◽  
And Migration ◽  
Adsorption Desorption ◽  
Sediment Interface

Deep-sea sediments with high contents of rare-earth elements and yttrium (REY) are expected to serve as a potential resource for REY, which have recently been proved to be mainly contributed by phosphate component. Studies have shown that the carriers of REY in deep-sea sediments include aluminosilicate, Fe-Mn oxyhydroxides, and phosphate components. The ∑REY of the phosphate component is 1–2 orders of magnitude higher than those of the other two carriers, expressed as ∑REY = 0.001 × [Al2O3] − 0.002 × [MnO] + 0.056 × [P2O5] − 32. The sediment P2O5 content of 1.5% explains 89.1% of the total variance of the sediment ∑REY content. According to global data, P has a stronger positive correlation with ∑REY compared with Mn, Fe, Al, etc.; 45.5% of samples have a P2O5 content of less than 0.25%, and ∑REY of not higher than 400 ppm. The ∑REY of the phosphate component reaches n × 104 ppm, much higher than that of marine phosphorites and lower than that of REY-phosphate minerals, which are called REY-rich phosphates in this study. The results of microscopic observation and separation by grain size indicate that the REY-rich phosphate component is mainly composed of bioapatite. When ∑REY > 2000 ppm, the average CaO/P2O5 ratio of the samples is 1.55, indicating that the phosphate composition is between carbonate fluoroapatite and hydroxyfluorapatite. According to a knowledge map of sediment elements, the phosphate component is mainly composed of P, Ca, Sr, REY, Sc, U, and Th, and its chemical composition is relatively stable. The phosphate component has a negative Ce anomaly and positive Y anomaly, and a REY pattern similar to that of marine phosphorites and seawater. After the early diagenesis process (biogeochemistry, adsorption, desorption, transformation, and migration), the REY enrichment in the phosphate component is completed near the seawater/sediment interface. In the process of REY enrichment, the precipitation and enrichment of P is critical. According to current research progress, the REY enrichment is the result of comprehensive factors, including low sedimentation rate, high ∑REY of the bottom seawater, a non-carbonate depositional environment, oxidation conditions, and certain bottom current conditions.

scholarly journals The application of137Cs and210Pbexmethods in soil erosion research of Titel loess plateau, Vojvodina, Northern Serbia

2020 ◽  
Vol 12 (1) ◽  
pp. 11-24
Author(s):  
Kristina S. Kalkan ◽  
Sofija Forkapić ◽  
Slobodan B. Marković ◽  
Kristina Bikit ◽  
Milivoj B. Gavrilov ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Loess Plateau ◽  
Alternative Methods ◽  
Delivery Ratio ◽  
Undisturbed Soil ◽  
Migration Model ◽  
Erosion Rates ◽  
Soil Erosion Rates ◽  
Profile Distribution ◽  
And Migration

AbstractSoil erosion is one of the largest global problems of environmental protection and sustainable development, causing serious land degradation and environmental deterioration. The need for fast and accurate soil rate assessment of erosion and deposition favors the application of alternative methods based on the radionuclide measurement technique contrary to long-term conventional methods. In this paper, we used gamma spectrometry measurements of 137Cs and unsupported 210Pbex in order to quantify the erosion on the Titel Loess Plateau near the Tisa (Tisza) River in the Vojvodina province of Serbia. Along the slope of the study area and in the immediate vicinity eight representative soil depth profiles were taken and the radioactivity content in 1 cm thick soil layers was analyzed. Soil erosion rates were estimated according to the profile distribution model and the diffusion and migration model for undisturbed soil. The net soil erosion rates, estimated by 137Cs method range from −2.3 t ha−1 yr−1 to −2.7 t ha−1 yr−1, related to the used conversion model which is comparable to published results of similar studies of soil erosion in the region. Vertical distribution of natural radionuclides in soil profiles was also discussed and compared with the profile distribution of unsupported 210Pbex measurements. The use of diffusion and migration model to convert the results of 210Pbex activities to soil redistribution rates indicates a slightly higher net erosion of −3.7 t ha−1 yr−1 with 98% of the sediment delivery ratio.

scholarly journals Intercity Migration and Migration Model

1969 ◽  
Vol 20 (2) ◽  
pp. 2-20,140
Author(s):  
Fumio Toishi
Keyword(s):  
Migration Model ◽  
And Migration

Some generalizations of Bailey's birth death and migration model

1970 ◽  
Vol 2 (01) ◽  
pp. 83-109 ◽  
Author(s):  
A. W. Davis
Keyword(s):  
Diffusion Process ◽  
Hypergeometric Functions ◽  
Spatial Location ◽  
Death Process ◽  
Birth And Death Process ◽  
Limiting Distributions ◽  
Migration Model ◽  
Branching Diffusion ◽  
And Migration ◽  
Natural Measures

Some results for a general Markov branching-diffusion process are presented, and applied to a model recently considered by Bailey. Moments of the limiting distributions of certain natural measures of the spatial location and dispersion of the population are shown to be expressible in terms of the LauricellaFD-type hypergeometric functions, when the population multiplies according to the simple birth and death process with λ > μ.

Cucurbitacins: A Systematic Review of the Phytochemistry and Anticancer Activity

2015 ◽  
Vol 43 (07) ◽  
pp. 1331-1350 ◽  
Author(s):  
Yuee Cai ◽  
Xiefan Fang ◽  
Chengwei He ◽  
Peng Li ◽  
Fei Xiao ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Mapk Signaling ◽  
Research Progress ◽  
Migration And Invasion ◽  
Invasion And Migration ◽  
Cycle Arrest ◽  
Anticancer Effects ◽  
And Migration

Cucurbitacins are highly oxidized tetracyclic triterpenoids that are widely present in traditional Chinese medicines (Cucurbitaceae family), possess strong anticancer activity, and are divided into 12 classes from A to T with over 200 derivatives. The eight most active cucurbitacin components against cancer are cucurbitacin B, D, E, I, IIa, L glucoside, Q, and R. Their mechanisms of action include antiproliferation, inhibition of migration and invasion, proapoptosis, and cell cycle arrest promotion. Cucurbitacins are also found to be the inhibitors of JAK-STAT3, Wnt, PI3K/Akt, and MAPK signaling pathways, which play important roles in the apoptosis and survival of cancer cells. Recently, new studies have discovered synergistic anticancer effects by using cucurbitacins together with clinically approved chemotherapeutic drugs, such as docetaxel and methotrexate. This paper provides a summary of recent research progress on the anticancer property of cucurbitacins and the various intracellular signaling pathways involved in the regulation of cancer cell proliferation, death, invasion, and migration. Therefore, cucurbitacins are a class of promising anticancer drugs to be used alone or be intergraded in current chemotherapies and radiotherapies to treat many types of cancers.

scholarly journals Effects of Anti-Angiogenesis on Glioblastoma Growth and Migration: Model to Clinical Predictions

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e115018 ◽  
Author(s):  
Elizabeth Scribner ◽  
Olivier Saut ◽  
Paula Province ◽  
Asim Bag ◽  
Thierry Colin ◽  
...  
Keyword(s):  
Migration Model ◽  
And Migration

Research progress in soil water/salt dynamics and crop growth under saline water irrigation

2011 ◽  
Vol 19 (4) ◽  
pp. 976-981
Author(s):  
Jing YANG ◽  
Ming-Xin YANG ◽  
Bao-Di DONG ◽  
Yun-Zhou QIAO ◽  
Chang-Hai SHI ◽  
...  
Keyword(s):  
Soil Water ◽  
Saline Water ◽  
Crop Growth ◽  
Research Progress ◽  
Saline Water Irrigation ◽  
Water Salt
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