157 research outputs found
PREDICTION PROGRAMMING OF THE WATER QUALITY AND ITS APPLICATION
This paper predicts the total phosphorus concentration in the water in the West Lake using a model of the convection and dispersion equation. The theory of the model is presented and predictions are made using a FORTRAN 77 program in a Dell 486 micro-computer. The results of numerical simulations are also discussed. The results presented in the paper have a practicable significance in controlling the environment of the water quality.Article信州大学理学部附属諏訪臨湖実験所報告 11: 99-108(1999)departmental bulletin pape
A CIRCULATION DYNAMICS MODEL IN THE ECOSYSTEM FOR THE WEST LAKE, HANGZHOU
This paper focuses the researches on an eutrophication model after drainage of wastewater and drawing water from the Qiantang River to West Lake. The model describes the circulation of nutritive matters (such as phosphorus, nitrogen, and carbon) in the ecosystem of the Lake. The model was established according to observed values of water quality and relevant parameters in 1995. The results of model calibration and verification show that the model can reasonably respond to the changes of forcing functions for drawing quantity and temperature of water. The model has been used to forecast the water quality in different drawing quantities. The predictions given by the model are also believed to be useful to comprehensively harness the West Lake.Article信州大学理学部附属諏訪臨湖実験所報告 11: 87-98(1999)departmental bulletin pape
Deterministic generation of skyrmions and antiskyrmions by electric current
Magnetic skyrmions are nanoscale spin whirlpools that promise breakthroughs
in future spintronic applications. Controlled generation of magnetic skyrmions
by electric current is crucial for this purpose. While previous studies have
demonstrated this operation, the topological charge of the generated skyrmions
is determined by the direction of the external magnetic fields, thus is fixed.
Here, we report the current-induced skyrmions creation in a chiral magnet FeGe
nanostructure by using the \emph{in-situ} Lorentz transmission electron
microscopy. We show that magnetic skyrmions or antiskyrmions can be both
transferred from the magnetic helical ground state simply by controlling the
direction of the current flow at zero magnetic field. The force analysis and
symmetry consideration, backed up by micromagnetic simulations, well explain
the experimental results, where magnetic skyrmions or antiskyrmions are created
due to the edge instability of the helical state in the presence of spin
transfer torque. The on-demand generation of skyrmions and control of their
topology by electric current without the need of magnetic field will enable
novel purely electric-controlled skyrmion devices.Comment: 5 pages and 4 figure
A giant glitch from the magnetar SGR J1935+2154 before FRB 200428
Fast radio bursts (FRBs) are short pulses observed in radio frequencies
usually originating from cosmological distances. The discovery of FRB 200428
and its X-ray counterpart from the Galactic magnetar SGR J1935+2154 suggests
that at least some FRBs can be generated by magnetars. However, the majority of
X-ray bursts from magnetars are not associated with radio emission. The fact
that only in rare cases can an FRB be generated raises the question regarding
the special triggering mechanism of FRBs. Here we report a giant glitch from
SGR J1935+2154, which occurred approximately \,day before FRB
200428, with {\rm Hz} and
\,pHz s. The corresponding spin-down power
change rate is among the largest in all the detected
pulsar glitches. The glitch contains a delayed spin-up process that is only
detected in the Crab pulsar and the magnetar 1E 2259+586, a large persistent
offset of the spin-down rate, and a recovery component which is about one order
of magnitude smaller than the persistent one. The temporal coincidence between
the glitch and FRB 200428 suggests a physical connection between the two. The
internally triggered giant glitch of the magnetar likely altered the
magnetosphere structure dramatically in favour of FRB generation, which
subsequently triggered many X-ray bursts and eventually FRB 200428 through
additional crustal cracking and Alfv\'en wave excitation and propagation
Microarray Profiling of TGF-β1-Induced Long Non-Coding RNA Expression Patterns in Human Lung Bronchial Epithelial BEAS-2B Cells
Background/Aims: TGF-β1 mediated radiation-induced bystander effects (RIBE) have been linked with malignant transformation and tumorigenesis. However, the underlying mechanisms are not fully understood. Methods: To reveal new molecules of regulatory functions in this process, lncRNA microarray was performed to profile both lncRNA and mRNA expression patterns in human lung bronchial epithelial BEAS-2B cells treated with TGF-β1 at a concentration measured in the medium conditioned by directly irradiated BEAS-2B cells. The potential functions of the differentially expressed lncRNAs were predicted by GO and KEGG pathway analyses of their co-expressed mRNAs. Cis- and trans-regulation of the lncRNAs were analyzed and the interaction networks were constructed using Cytoscape. qRT-PCR was conducted to validate the results of microarray profiling. CCK-8 assay was employed for functional validation of 3 identified lncRNAs. Results: 224 lncRNAs were found to be dysregulated, among which 6 lncRNAs were chosen for expression validation by qRT-PCR assay. Pathway analyses showed that differentially expressed lncRNAs are highly correlated with cell proliferation, transformation, migration, etc. Trans-regulation analyses showed that the differentially expressed lncRNAs most likely participate in the pathways regulated by four transcriptional factors, FOS, STAT3, RAD21 and E2F1, which have been identified to be involved in the modulation of oncogenic transformation, cell cycle progression, genomic instability, etc. lnc-THEMIS-2 and lnc-ITGB6-4, predicted to be regulated by STAT3 and E2F1 respectively, were found to rescue the decrease of cell viability induced by TGF-β1 treatment. Conclusion: Our findings suggest that the differentially expressed lncRNAs induced by TGF-β1 play crucial roles in the oncogenic transformation and tumorigenesis, which provide a better understanding of the underlying mechanisms related to tumorigensis induced by LD/LDR radiations
Neural Chinese Word Segmentation with Lexicon and Unlabeled Data via Posterior Regularization
Existing methods for CWS usually rely on a large number of labeled sentences
to train word segmentation models, which are expensive and time-consuming to
annotate. Luckily, the unlabeled data is usually easy to collect and many
high-quality Chinese lexicons are off-the-shelf, both of which can provide
useful information for CWS. In this paper, we propose a neural approach for
Chinese word segmentation which can exploit both lexicon and unlabeled data.
Our approach is based on a variant of posterior regularization algorithm, and
the unlabeled data and lexicon are incorporated into model training as indirect
supervision by regularizing the prediction space of CWS models. Extensive
experiments on multiple benchmark datasets in both in-domain and cross-domain
scenarios validate the effectiveness of our approach.Comment: 7 pages, 11 figures, accepted by the 2019 World Wide Web Conference
(WWW '19
The prognostic impact of preoperative blood monocyte count in pathological T3N0M0 rectal cancer without neoadjuvant chemoradiotherapy
Preparation of Pb-doped tailings-based nano-TiO2 and study on photocatalytic degradation of PAM wastewater
As an efficient flocculant, polyacrylamide (PAM) is widely used in water treatment process. The acrylamide monomer (AM) produced by depolymerization of residual PAM has been listed as a class IIA carcinogen, and its treatment is imminent. Flotation tailing (TC) was used as raw material to prepare a modified tailing matrix by alkali excitation. Nano-TiO2 was loaded onto the modified tailing matrix by hydrothermal method to prepare tailing-based nano-TiO2 composite (TiO2/TC) and Pb-doped tailing-based nano-TiO2 composite (Pb-TiO2/TC). The photocatalytic degradation properties of TC, modified coal matrix, TiO2/TC and Pb-TiO2/TC were analyzed with PAM as the target pollutant. The samples were characterized by XRD, SEM, UV-vis and BET, and the degradation products were analyzed and studied by high performance liquid chromatography-mass spectrometry. The degradation mechanism of PAM was explored. The results show that TC is irregular and the surface is rough; the surface of TiO2/TC is loose, the pore structure is obvious, and the fine tubular TiO2 is uniformly coated on the surface of modified tailings. The structure of Pb-TiO2/TC is more fluffy, and the modified coal matrix is loaded with more tubular TiO2. The band gap of TiO2/TC was 3.16 eV, and Pb2+ doping reduced the band gap of Pb-TiO2/TC to 3.08 eV. The specific surface area of TiO2 is 286.66 m2/g, the specific surface area of TiO2/TC and Pb-TiO2/TC are 360.33 m2/g and 358.54 m2/g. The higher specific surface area provides more active sites for the reaction, and the adsorption-catalytic synergistic effect significantly improves the photocatalytic efficiency. The degradation rates of PAM by TC and modified tailing matrix were 3.39% and 4.68%. The degradation rates of polyacrylamide by TiO2/TC and Pb-TiO2/TC loaded with TiO2 increased to 38.92% and 63.87%. After five cycles, the photocatalytic properties of TiO2/TC and Pb-TiO2/TC remained basically unchanged. In the degradation process of PAM, the macromolecular PAM breaks into small molecular weight PAM molecules, and further decomposes into NO3−, acrylic acid, acetamide and acetic acid
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