Ultrafast Modulation of the Molten Metal Surface Tension under Femtosecond Laser Irradiation

We predict ultrafast modulation of the pure molten metal surface stress fields under the irradiation of the single femtosecond laser pulse through the two-temperature model molecular-dynamics simulations. High-resolution and precision calculations are used to resolve the ultrafast laser-induced anisotropic relaxations of the pressure components on the time-scale comparable to the intrinsic liquid density relaxation time. The magnitudes of the dynamic surface tensions are found being modulated sharply within picoseconds after the irradiation, due to the development of the nanometer scale non-hydrostatic regime behind the exterior atomic layer of the liquid surfaces.The reported novel regulation mechanism of the liquid surface stress field and the dynamic surface tension hints at levitating the manipulation of liquid surfaces, such as ultrafast steering the surface directional transport and patterning.

Effect of hypoxia on migration, invasion and adhesion to endothelium of human pulmonary adenocarcinoma A549 cells

Objective： To evaluate the effect of hypoxia on migration, invasion and adhesion to endothelium of human pulmo- nary adenocarcinoma A549 cells. Methods： Wound-healing and Transwell invasion assays were performed to study the effect of hypoxia on migration and invasion of A549 cells, and A549 cells were added to a monolayer of human umbilical vein endo-thelial cells （HUVECs） to test the ability to adhere to endothelium. Immunofluorescence assay and luciferase reporter gene assay were also used to evaluate the effect of hypoxia on distribution of E-cadherin, β-catenin, and actin, and hypoxia-inducible factor-1 （HIF-1）-dependent transcription, respectively. Results： Hypoxia facilitated A549 cell migration, invasion, and A549 cell-endothelial cells adhesion, and modulated the distribution of E-cadherin and β-catenin, and actin cytoskeleton rearrange-ment, and up-regulated HIF-l-dependent reporter gene expression in A549 cells. Conclusion： Promotion ofA549 cell migration, invasion, and adhesion on endothelium by hypoxia might be modulated through its up-regulating HIF-l-dependent gene expression, which then induced the redistribution of E-cadherin and β-catenin, and the actin cytoskeletal reorganization.

Route selection for opportunity-sensing and prediction of waterlogging

Accurate monitoring of urban waterlogging contributes to the city’s normal operation and the safety of residents’daily travel.However,due to feedback delays or high costs,existing methods make large-scale,fine-grained waterlogging monitoring impossible.A common method is to forecast the city’s global waterlogging status using its partial waterlogging data.This method has two challenges:first,existing predictive algorithms are either driven by knowledge or data alone;and second,the partial waterlogging data is not collected selectively,resulting in poor predictions.To overcome the aforementioned challenges,this paper proposes a framework for large-scale and fine-grained spatiotemporal waterlogging monitoring based on the opportunistic sensing of limited bus routes.This framework follows the Sparse Crowdsensing and mainly comprises a pair of iterative predictor and selector.The predictor uses the collected waterlogging status and the predicted status of the uncollected area to train the graph convolutional neural network.It combines both knowledge-driven and data-driven approaches and can be used to forecast waterlogging status in all regions for the upcoming term.The selector consists of a two-stage selection procedure that can select valuable bus routes while satisfying budget constraints.The experimental results on real waterlogging and bus routes in Shenzhen show that the proposed framework could easily perform urban waterlogging monitoring with low cost,high accuracy,wide coverage,and fine granularity.

Incremental cost analysis model of distribution network based on economic dispatch of distributed new-energy storage system

With the implementation of China’s carbon-peaking and carbon-neutrality strategy,new energy will achieve leapfrog growth.Due to the good economics of distributed new-energy generation,it can not only save users’own investment,but also help to achieve local consumption of new energy.However,it will also bring about a series of incremental costs to the power grid.This paper first enumerates the concept,development status and scheduling mode of a distributed new-energy storage system.Based on the above,it establishes a new-energy power generation model and an energy storage system charging and discharging model,and proposes a global optimization scheduling model for a distributed new-energy storage system,considering the time-of-use electricity price and taking the lowest total operating cost of the distributed new-energy power generation system as the objective function.Finally,it proposes a distribution network incremental cost analysis model based on the penetration of distributed new energy.The calculation results show that the incremental cost of grid-connected distributed new energy is 1.0849,1.2585 and 1.3473 yuan/kWh,respectively,which indicates that the global dispatching model can optimize the power consumption structure of a distributed power generation system,and has the function of peak shaving and valley filling,but the incremental cost of the distribution network will also increase.

Study on multi-timescale operation of hydrogen-containing energy coupled with transportation system

With the widespread attention on hydrogen energy,the operation optimization of the coupling system of hydrogen energy and transportation has become a critical issue.Therefore,this study develops a hydrogen-containing energy transportation coupling system for the system collaborative operation framework,operation mode and equipment modelling of the system.Furthermore,a medium-to long-term operation optimization model and a short-term operation optimization model were constructed considering the differences in the operation of coupled systems at different timescales and operating costs as the objective function and power balance and system equipment as constraints.In the medium-and long-term operation optimization model,the planning scenario reduction method is used to reduce the wind power generation scenario.In the short-term operation optimization model,a multivariate uncertainty model is constructed to represent the uncertainty in the coupling system.Subsequently,the solution method of the model is proposed.Finally,a coupled system is simulated to verify the effectiveness of the model.(i)When the initial scene set is 600,the typical scene reduction method using Latin hypercube sampling and the Wasserstein distance can reduce operating costs by 7.60%and 9.49%compared with K-means reduction and K-media reduction methods.(ii)The sensitivity coefficients of hydrogen sales price,electricity sales price and maintenance rate to operating costs are-0.031%,-1.009%and 0.0105%,respectively.(iii)Considering multiple uncertainties can help make optimal decisions based on the overall consideration of disadvantage scenarios,thereby reducing system operating costs.

Simultaneous quantification of fifty-one odor-causing compounds in drinking water using gas chromatography-triple quadrupole tandem mass spectrometry

A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2> 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.

Leaching behavior of enrofloxacin in three different soils and the influence of a surfactant on its mobility

The leaching behaviors of enrofloxacin （ENR）, a fluoroquinolone group antibiotic, in three different standard soils, namely sandy, loamy sand and sandy loam were investigated according to OECD guideline 312. In addition, the effects of tenside, sodium dodecylbenzenesulfonate （DBS） on the mobility of ENR in two different soils were studied. The mobility of ENR in all three standard soils was very similar and was mostly （98%） concentrated on the top 0-5 cm segment of the soils at pH 5.7. The DBS can enhance the mobility of ENR in soils but the impact was in general negligible under the studied conditions.

S incorporated RuO_(2)-based nanorings for active and stable water oxidation in acid

The design of highly active and stable RuO_(2)-based nanostructures for acidic oxygen evolution reaction(OER)is extremely important for the development of water electrolysis technology,yet remains great challenges.We here demonstrate that the incorporation of S into RuCuO nanorings(NRs)can significantly enhance the acidic OER performance.Experimental investigations show that the incorporation of S can optimize the interaction of Ru and O,and therefore significantly suppresses the dissolution of Ru in acidic condition.The optimized catalyst(SH-RuCuO NRs)displays superior OER performance to the commercial RuO_(2)/C.Impressively,the SH-RuCuO NRs can exhibit significantly enhanced stability for 3,000 cycles of cyclic voltammetry test and more than 250 h chronopotentiometry test at 10 mA·cm^(-2)in 0.5 M H_(2)SO_(4).This work highlights a potential strategy for designing active and stable RuO_(2)-based electrocatalysts for acidic OER.

Atomically isolated Pd sites within Pd-S nanocrystals enable trifunctional catalysis for direct,electrocatalytic and photocatalytic syntheses of H_(2)O_(2)

Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging yet desirable.Herein,for the first time we reported that palladium-sulphur nanocrystals(Pd-S NCs)can be adopted as robust and universal catalysts,which can realize the efficient O_(2) conversion by three methods.As a result,Pd-S NCs exhibit an excellent selectivity(89.5%)to H_(2)O_(2)with high productivity(133.6 mol·kgcat^(−1)·h^(−1))in the direct synthesis,along with the significantly enhanced H_(2)O_(2)production activity and stability via electrocatalytic and photocatalytic syntheses.It is demonstrated that the isolated Pd sites can enhance the adsorption of O_(2) and inhibit its O–O bond dissociation,improving H_(2)O_(2)selectivity and reducing H_(2)O_(2)degradation.Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.

Pivotal roles of tumor-draining lymph nodes in the abscopal effects from combined immunotherapy and radiotherapy

Background:Currently,due to synergy enhancement of anti-tumor effects and potent stimulation of abscopal effects,combination therapy with irradiation and programmed cell death protein 1/programmed death-ligand 1(PD-1/PD-L1)immune checkpoint inhibition(immuno-radiotherapy,iRT)has revolutionized the therapeutic guidelines.It has been demonstrated that tumor-draining lymph nodes(TDLN)are essential for effective antitumor immunity induced by radiotherapy,immunotherapy,or iRT.Given that the function of TDLN in iRT remains unclear,this study aimed to investigate the function and mechanism of TDLN in iRT-induced abscopal effects.Methods:The function of TDLN was evaluated using unilateral or bilateral MC38 and B16F10 subcutaneous tumor models with or without indicated TDLN.The flow cytometry,multiple immunofluorescence analysis,and NanoString analysis were utilized to detect the composition and function of the immune cells in the primary and abscopal tumor microenvironment.Additionally,we tempted to interrogate the possible mechanisms via RNA-sequencing of tumor-infiltrating lymphocytes and TDLN.Results:TDLN deficiency impaired the control of tumor growth by monotherapy.Bilateral TDLN removal rather than unilateral TDLN removal substantially curtailed iRT-stimulated anti-tumor and abscopal effects.Furthermore,in the absence of TDLN,the infiltration of CD45+and CD8+T cells was substantially reduced in both primary and abscopal tumors,and the anti-tumor function of CD8+T cells was attenuated as well.Additionally,the polarization of tumor-associated macrophages in primary and abscopal tumors were found to be dependent on intact bilateral TDLN.RNA-sequencing data indicated that impaired infiltration and anti-tumor effects of immune cells partially attributed to the altered secretion of components from the tumor microenvironment.Conclusions:TDLN play a critical role in iRT by promoting the infiltration of CD8+T cells and maintaining the M1/M2 macrophage ratio.

Identification of unknown disinfection byproducts in drinking water produced from Taihu Lake source water

Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry(LC-QTOF MS) to identify the unknown disinfection byproducts(DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surrounding regions. In total, 91 formulas of DBPs were discovered through LC-QTOF MS nontarget screen, 81 of which have not yet been reported. Among the 91 molecules, 56 only contain bromine, 15 only contain chlorine and 20 DBPs have both bromine and chlorine atoms. Finally, five DBPs including 2,4,6-tribromophenol, 2,6-dibromo-4-chlorophenol, 2,6-dichloro-4-bromophenol, 4-bromo-2,6-di-tert-butylphenol and 3,6-dibromocarbazole were confirmed using standards. The former three compounds mainly formed in the predisinfection step(maximum concentration, 0.2-2.6 μg/L), while the latter two formed in the disinfection step(maximum concentration, 18.2-33.6 ng/L). In addition, 19 possible precursors of the discovered DBPs were detected, with the aromatic compounds being a major group. 2,6-di-tert-butylphenol as the precursor of 4-bromo-2,6-di-tert-butylphenol was confirmed with standard, with a concentration of 20.3 μg/L in raw water. The results of this study show that brominated DBPs which are possibly formed from industrial pollutants are relevant DBP species in drinking water produced form Taihu source water, suggesting protection of Taihu Lake source water is important to control the DBP risks.

A framework based on sparse representation model for time series prediction in smart city

Smart city driven by Big Data and Internet of Things(loT)has become a most promising trend of the future.As one important function of smart city,event alert based on time series prediction is faced with the challenge of how to extract and represent discriminative features of sensing knowledge from the massive sequential data generated by IoT devices.In this paper,a framework based on sparse representa-tion model(SRM)for time series prediction is proposed as an efficient approach to tackle this challenge.After dividing the over-complete dictionary into upper and lower parts,the main idea of SRM is to obtain the sparse representation of time series based on the upper part firstly,and then realize the prediction of future values based on the lower part.The choice of different dictionaries has a significant impact on the performance of SRM.This paper focuses on the study of dictionary construction strategy and summarizes eight variants of SRM.Experimental results demonstrate that SRM can deal with different types of time series prediction flexibly and effectively.

Indefinite stochastic linear-quadratic optimal control problems with random jumps and related stochastic Riccati equations

We discuss the stochastic linear-quadratic(LQ) optimal control problem with Poisson processes under the indefinite case. Based on the wellposedness of the LQ problem, the main idea is expressed by the definition of relax compensator that extends the stochastic Hamiltonian system and stochastic Riccati equation with Poisson processes(SREP) from the positive definite case to the indefinite case. We mainly study the existence and uniqueness of the solution for the stochastic Hamiltonian system and obtain the optimal control with open-loop form. Then, we further investigate the existence and uniqueness of the solution for SREP in some special case and obtain the optimal control in close-loop form.

Linear-quadratic generalized Stackelberg games with jump-diffusion processes and related forward-backward stochastic differential equations

A kind of linear-quadratic Stackelberg games with the multilevel hierarchy driven by both Brownian motion and Poisson processes is considered.The Stackelberg equilibrium is presented by linear forward-backward stochastic differential equations(FBSDEs)with Poisson processes(FBSDEPs)in a closed form.By the continuity method,the unique solvability of FBSDEPs with a multilevel self-similar domination-monotonicity structure is obtained.

BACKWARD STOCHASTIC VIABILITY AND RELATED PROPERTIES ON Z FOR BSDES WITH APPLICATIONS

This paper investigates some important properties of Z, the martingale integrant of the backward stochastic differential equations, which is the second process of the solution. These include the backward stochastic viability property, bounded property and the comparison theorem. To explain the theoretical results, the authors apply them to study a financial contingent claim pricing problem. The replication portfolio process can be characterized clearly.

Structure and electrical properties of ternary BiFeO_(3)-BaTiO_(3)-PbTiO_(3) high-temperature piezoceramics

In the current work,the bulk ternary(0.85-x)BiFeO3-xBaTiO3-0.15PbTiO3(BF-BTx-PT,x=0.08-0.35)system has been studied as a potential high-temperature piezoceramics.Samples with various content of BT were prepared via solid-state route,and pure perovskite phase was confirmed by X-ray diffraction.The temperature dependence of dielectric constants confirmed the decrease of Curie temperature with increasing BT content.It was found that the morphotropic phase boundary(MPB)composition of BF-BTx-PT ceramics was in the vicinity of x=0.15,which exhibits optimal properties with piezoelectric constant d33 of 60 pC/N,high Curie temperature of 550℃,and low sintering temperature of 920℃.Measurements also showed that the depoling temperature was 300℃,about 150℃higher than that of commercialized PZT ceramics,which indicated good temperature stability.BF-BTx-PT ceramics are promising candidates for high temperature applications.

Mean-field type FBSDEs in a domination-monotonicity framework and LQ multi-level Stackelberg games

Motivated by various mean-field type linear-quadratic(MF-LQ,for short)multilevel Stackelberg games,we propose a kind of multi-level self-similar randomized dominationmonotonicity structures.When the coefficients of a class of mean-field type forwardbackward stochastic differential equations(MF-FBSDEs,for short)satisfy this kind of structures,we prove the existence,the uniqueness,an estimate and the continuous dependence on the coefficients of solutions.Further,the theoretical results are applied to construct unique Stackelberg equilibria for forward and backward MF-LQ multi-level Stackelberg games,respectively.

INFLUENCE OF CaF_(2)-4LiF ADDITIVE ON SINTERING AND ENERGY STORAGE PERFORMANCE OF SrTiO_(3)CERAMICS

The CaF_(2)-4LiF additive was added into SrTiO_(3)ceramics in order to decrease the sintering temperature for compact pulse power application.The crystalline structure,microstructure and energy storage performance of sintered ceramics were studied.Incorporating CaF_(2)-4LiF additive to SrTiO_(3)ceramics contributes to a notably enhancement of the energy storage density.The great enhancement in energy storage density occurred due to the notable increase in breakdown strength and the refinement of microstructure.With 2 at%additive,the samples exhibited an average breakdown strength of 31.8kV/mm,and an energy storage density of 1.212 J/cm^(3)which is about 1.4 times higher than pure SrTiO_(3).