Here we present one of the world’s oldest examples of large-scale and formalized water management, in the case of the Liangzhu culture of the Yangtze Delta, dated at 5,300–4,300 years cal B.P. The ...Liangzhu culture represented a peak of early cultural and social development predating the historically recorded Chinese dynasties; hence, this study reveals more about the ancient origins of hydraulic engineering as a core element of social, political, and economic developments. Archaeological surveys and excavations can now portray the impressive extent and structure of dams, levees, ditches, and other landscape-transforming features, supporting the ancient city of Liangzhu, with an estimated size of about 300 ha. The results indicate an enormous collective undertaking, with unprecedented evidence for understanding how the city, economy, and society of Liangzhu functioned and developed at such a large scale. Concurrent with the evidence of technological achievements and economic success, a unique relationship between ritual order and social power is seen in the renowned jade objects in Liangzhu elite burials, thus expanding our view beyond the practicalities of water management and rice farming.
Two-dimensional phase unwrapping is a key step in the phase extraction process, an image-processing stage that is common to many different systems. Many varied approaches have been proposed over the ...past several decades. However, with the growth of image scale, it poses new challenges in terms of computational and memory requirements to phase unwrapping that require a global approach to obtain good results. Owing to only a single process used in most previous algorithm implementations, it becomes more problematic to unwrapping when the required computing resources exceed the capability of one computer. Meanwhile, with the development and application of supercomputer techniques, high-performance computing is emerging as a promising platform for scientific applications. In this paper, a novel hybrid multiprocessing and multithreading algorithm is proposed in order to overcome the problem of unwrapping large data sets. In this algorithm, we improve on Goldstein's branch-cut algorithm using simulated annealing idea to further optimize the set of branch cuts in parallel. For large data sets, the tiling strategy based on the nature of parallel computing guarantees the globality of phase unwrapping and avoids large-scale errors introduced. Using real and simulated interferometric data, we demonstrate that our algorithms are highly competitive with other existing algorithms in speed and accuracy. We also demonstrate that the proposed algorithm can be efficiently parallelized and performed across nodes in a high-performance computing cluster.
Flooding represents one of the most severe natural disasters threatening the
development of human society. A model that is capable of predicting the
hydrological responses in watershed with ...management practices during flood
period would be a crucial tool for pre-assessment of flood reduction
measures. The Soil and Water Assessment Tool (SWAT) is a semi-distributed
hydrological model that is well capable of runoff and water quality modeling
under changed scenarios. The original SWAT model is a long-term yield model.
However, a daily simulation time step and a continuous time marching limit
the application of the SWAT model for detailed, event-based flood simulation.
In addition, SWAT uses a basin level parameter that is fixed for the whole
catchment to parameterize the unit hydrograph (UH), thereby ignoring the
spatial heterogeneity among the sub-basins when adjusting the shape of the
UHs. This paper developed a method to perform event-based flood simulation on
a sub-daily timescale based on SWAT2005 and simultaneously improved the UH
method used in the original SWAT model. First, model programs for surface
runoff and water routing were modified to a sub-daily timescale.
Subsequently, the entire loop structure was broken into discrete flood events
in order to obtain a SWAT-EVENT model in which antecedent soil moisture and
antecedent reach storage could be obtained from daily simulations of the
original SWAT model. Finally, the original lumped UH parameter was refined
into a set of distributed ones to reflect the spatial variability of the
studied area. The modified SWAT-EVENT model was used in the Wangjiaba
catchment located in the upper reaches of the Huaihe River in China. Daily
calibration and validation procedures were first performed for the SWAT model
with long-term flow data from 1990 to 2010, after which sub-daily
(Δt=2 h) calibration and validation in the SWAT-EVENT model
were conducted with 24 flood events originating primarily during the flood
seasons within the same time span. Daily simulation results demonstrated that
the SWAT model could yield very good performances in reproducing streamflow
for both whole year and flood period. Event-based flood simulation results
simulated by the sub-daily SWAT-EVENT model indicated reliable performances,
with ENS values varying from 0.67 to 0.95. The SWAT-EVENT
model, compared to the SWAT model, particularly improved the simulation
accuracies of the flood peaks. Furthermore, the SWAT-EVENT model results of
the two UH parameterization methods indicated that the use of the distributed
parameters resulted in a more reasonable UH characterization and better model
fit compared to the lumped UH parameter.
Classical molecular dynamic simulations are performed to investigate the microscopic properties of hexadecyltrimethylammonium (HDTMA) intercalated smectites with and without the cointercalation of ...acetate groups. Three model smectites with distinct layer-charge characteristics are selected as the frameworks and their HDTMA intercalates correspond to the representative monolayer, bilayer, and paraffin configurations of the aliphatic chains. In the organoclays without cointercalation, all trimethylammonium headgroups of HDTMA are fixed firmly above the center of the surface six-member rings through electrostatic attractions with surface oxygen, whereas the alkyl chains are a little more mobile. It is found that the cointercalations can significantly increase the basal spacings of the pure HDTMA intercalated smectites. The distributions and mobility of the HDTMA headgroups are not affected by the acetate ions because of the overwhelming attractions coming from the clay sheets. The acetate groups are fixed by the HDTMA headgroups through ion pairing. This simulation study provides a molecular level basis to understand the effects of cointercalation on properties of organoclays.
With the rapid growth of various complex networks, link prediction has become increasingly important because it can discover the missing information and predict future interactions between nodes in a ...network. Recently, the CAR and CCLP indexes have been presented for link prediction by means of different triangle structure information. However, both indexes may lose the contributions of some shared neighbors. We propose in this work a new index to make up the weakness and then improve the accuracy of link prediction. The proposed index focuses on a new triangle structure, i.e., the triangle formed by one seed node, one common neighbor, and one other node. It emphasizes the importance of these triangles but does not ignore the contribution of any common neighbor. In addition, the proposed index adopts the theory of resource allocation by penalizing large-degree neighbors. The results of comparison with CN, AA, RA, ADP, CAR, CAA, CRA, and CCLP on 12 real-world networks show that the proposed index outperforms the compared methods in terms of AUC and ranking score.
Link prediction is one of the research hotspots in complex network analysis and has a wide range of applications in both theory and reality. To improve the prediction accuracy, this paper proposes a ...new link prediction framework by considering both node similarity and community information, which overcomes the weaknesses of existing community-based prediction methods. In the proposed framework, a reasonable measure, called community relationship strength (CRS), is defined to estimate the closeness between communities. In this paper, we hold the view that the connection likelihood between two target nodes rests upon not only their similarity but also the closeness of communities that they belong to. Therefore, to measure the connection likelihood, the proposed framework combines CRS with traditional similarity indexes. Three CRS-based methods are derived from the framework. The performance of the CRS-based methods is comprehensively studied on 12 real-world networks compared with several groups of baselines. The experimental results indicate that the CRS-based methods are more effective and robust than others.
To shed light on gold speciation in sulfur-containing ore-forming fluids, we perform first principles molecular dynamics (FPMD) simulations to investigate gold–hydrosulphide complexing under ...representative geological conditions. With this advanced technique, the electronic structures of solutes and solvents are calculated with density functional theory and the thermal motions are sampled with molecular dynamics. The molecular structures, solvated structures and stabilities of possible complexes are characterized in detail and the following insights have been gained. (1) The previously hypothesized species Au(HS)(H
2S)
3 and Au(HS) are found unstable under ore-forming conditions. Au(HS)(H
2S)
3 would dissociate to LAu(HS) (L
=
H
2S or H
2O) and free H
2S molecules spontaneously. Au(HS) is highly reactive and tends to capture a second ligand to form a double-coordinated complex. (2) In the thin vapor-like phases of low pressures, the stable complexes include Au(HS)(H
2O), Au(HS)(H
2S) and Au(HS)
2
− and their relative stability is Au(HS)
2
−
>
Au(HS)(H
2S)
>
Au(HS)(H
2O). In dense aqueous phases of high pressures, Au(HS)(H
2S) would spontaneously deprotonate to Au(HS)
2
− and thus Au(HS)(H
2O) and Au(HS)
2
− are the stable forms. All of these complexes can retain to the upper-limit of ore-forming temperatures. (3) The gold ions in the complexes do not favor coordinating more molecules and therefore the solvations happen mainly through H-bonding interactions between the ligands and environmental waters. H-bonds are found in vapor, liquid, and dense supercritical phases, whereas in the thin supercritical phase the hydration is very weak. These results provide quantitative and microscopic basis for understanding the speciation of gold in hydrothermal fluids.
BRD4 is a member of the BET protein family involved in chromatin remodeling and transcriptional regulation. Several BET inhibitors (BETi) have entered clinical trials, demonstrating potential in ...inducing cancer cell apoptosis and tumor regression. However, resistance to BETi is common in solid tumors. In pancreatic cancer, it is found that cancer-associated fibroblasts (CAFs) in the tumor microenvironment reduce the BET inhibitor JQ1 sensitivity by inducing BRD4 expression. Moreover, CAFs play a crucial role in the formation of a dense stromal barrier. Therefore, targeting CAFs in the tumor microenvironment of pancreatic cancer not only enhances cancer cells sensitivity to JQ1 but also increases drug perfusion and improves oxygen supply, thus reducing glycolysis and limiting energy supply. To address this challenge, a homologous targeting mechanism utilizing activated fibroblast membrane-coated liposomes is proposed for specific drug precise target to CAFs-rich pancreatic cancer. Additionally, TAT peptides enable liposomes penetration, delivering PFD for targeted anti-fibrotic therapy, reducing extracellular matrix generation and glycolysis, and enhancing JQ1 delivery and sensitivity. In conclusion, the findings indicate the tremendous potential of this CAFs-targeting liposomal delivery system in pancreatic cancer.
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