Changing political and market conditions have disrupted energy security.European economies are planning to utilize their own resources of energy raw materials,including consideration of the advisability of returning a...Changing political and market conditions have disrupted energy security.European economies are planning to utilize their own resources of energy raw materials,including consideration of the advisability of returning abandoned coal resources to use.The research using the proposed methodology examined the impact of the ongoing mine closure processes on the potential ability to develop the remaining deposit.It was found that the greatest influence on the availability of unclosed shafts was the active concession to extract minerals from the deposit and the availability of unclosed main plant facilities.The assessment of the possibilities of coal resources management in the deposits of liquidated mines has not been the subject of extensive scientific research so far.The information obtained can be used as a reference point for detailed analysis and multi-criteria evaluation,after which the decision maker makes the decision.The method is designed for liquidated mines,but with certain modifications it can also be used by mining companies.展开更多
The extended trading close(ETC)provides institutional investors an opportunity to trade at the closing price after the regular trading session(RTS)and disclosing the order imbalances to other market participants.ETCs ...The extended trading close(ETC)provides institutional investors an opportunity to trade at the closing price after the regular trading session(RTS)and disclosing the order imbalances to other market participants.ETCs exist in the Nasdaq,the SSE STAR,the SZSE ChiNext and the TWSE.To help a risk-averse institutional investor take advantage of the RTS and the ETC for liquidation,we develop a multistage dynamic programming model including the ETC,and derive recursive solutions for the multiple trading days scenario with closed-form solutions for the scenario with only two trading days.We also verify that the ETC is able to mitigate extreme price movements caused by fast liquidation,which is also a goal of the ETC set out by the SSE STAR and the SZSE ChiNext.Finally,we derive three results.First,an institutional investor can reduce execution costs after the introduction of the ETC.Second,a critical trading day exists,and to avoid prematurely revealing trading intentions,the investor should not trade in the ETC until such day.Third,even though the ETC orders submitted by the investor are unfilled,implementation of the ETC encourages the investor to change the liquidation strategy in the RTS,which reduces extreme price movements.In summary,the practical implications of this paper are that the investor should not trade during the ETC on the front few days to avoid prematurely revealing the investor’s trading intention by unfilled orders in the ETC and that introducing the ETC can reduce liquidation costs and extreme price movements.展开更多
Doing business in China, while lucrative, can be a minefield to the uninitiated. This regular column by Deloitte will provide specific information to give businesspeople the tools they need to facilitate this process.
We propose a forward approach to study the performance of liquidation strategies under sequential model parameter updates.The forward liquidation program consists of pasting forward in time and in a time-consistent fa...We propose a forward approach to study the performance of liquidation strategies under sequential model parameter updates.The forward liquidation program consists of pasting forward in time and in a time-consistent fashion a series of optimal liquidation problems.They are triggered at the parameter shift instances,thus entirely eliminating model error,and last at most till the next parameter update.However,due to the nature of the model dynamics,solutions may cease to exist in finite time,even before the subsequent parameter update.Furthermore,forward liquidation strategies may never lead to full liquidation,even though they maximize the average utility of revenue and always preserve time-consistency.In juxtaposition,the traditional approach delivers full liquidation at the sought horizon but encounters considerable model error,generates value erosion,and is time-inconsistent.展开更多
Based on the minimum loss probability criterion,this paper discusses the optimal strategy in multi-asset liquidation.First,we give the framework of the multi-asset liquidation problem and obtain the boundary condition...Based on the minimum loss probability criterion,this paper discusses the optimal strategy in multi-asset liquidation.First,we give the framework of the multi-asset liquidation problem and obtain the boundary conditions of the optimal liquidation strategy under the assumption of linear price impact functions and transform the multi-asset liquidation problem into the portfolio liquidation problem.On this basis,the asymptotic solution and numerical solution of the optimal liquidation strategy are obtained.Then,we simulate the trajectories of the optimal liquidation strategy and analyze the effects of parameters changes.展开更多
This paper proposes a two-period model to examine which bankruptcy procedure is better for both the debtor and creditor when insolvency happens.Our theoretical model depicts how firm size,industry characteristics,equi...This paper proposes a two-period model to examine which bankruptcy procedure is better for both the debtor and creditor when insolvency happens.Our theoretical model depicts how firm size,industry characteristics,equity structure,and debt structure determine firms’bankruptcy resolutions.Using a comprehensive sample of bankrupt firms in the United States,we verify the predictions of a theoretical model.In our study,we deploy Probit and Logit models to address the predictions in the theoretical framework and conduct a series of robustness checks with econometric methods like Propensity Score Matching to confirm the empirical results.This paper finds that firms with larger size have more chance to file for Chapter 11 reorganization when insolvency happens.We also find that firms in asset-heavy(asset-light)industries are more likely to be reorganized(liquidated)under U.S.bankruptcy code.展开更多
In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with l...In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.展开更多
The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of ris...The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.展开更多
A reversed-phase high-performance liquid chromatography(HPLC)method was developed for the direct determination of docosahexaenoic acid(DHA)in sturgeon caviar extract.The assay employed n-hexane extraction combined wit...A reversed-phase high-performance liquid chromatography(HPLC)method was developed for the direct determination of docosahexaenoic acid(DHA)in sturgeon caviar extract.The assay employed n-hexane extraction combined with gradient elution(ZORBAX SB-C18 column),with data collected using a diode array detector.The content was calculated by external standard method and validated against the national standard(GB 5009.168-2016).The study also measured DPPH free radical scavenging capacity and moisture retention rate across different DHA concentration groups.The results demonstrate that the proposed method exhibits excellent linearity(r=0.9997),with recovery rates ranging from 92.1% to 101.1% and relative standard deviations(RSD)of 2.23% to 3.92%.Compared to the national standard method,the relative deviation was 0.67% to 1.68%.At specific test concentrations,the high-DHA group shows significantly higher moisture retention(100.48%),hygroscopicity(100.85%),and DPPH scavenging efficiency(57.46%)than the low-DHA group(10.33%,11.76%,and 3.71%).The RP-HPLC method developed in this study simplifies DHA detection procedures with simple reagents and reliable results,making it suitable for rapid qualitative identification and quantitative analysis of target components in caviar extract quality control.The DPPH experiment further reveals the correlation between DHA content and antioxidant efficacy in sturgeon caviar extracts,providing scientific evidence for developing functional cosmetics.展开更多
Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high...Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high condensate content,high temperature,and high salinity)often affect foaming agent performance.In this study,surfactants were screened using an airflow method that closely resembles field treatment method.Notably,alcohol ether sulfates(AE_(n)S)with various polyoxyethylene(EO)units demonstrated exceptional performance in terms of liquid unloading efficiency and foam stability.At 80℃,the unloading efficiency of AE_(n)S with two EO units(AE_(2)S)in a high NaCl mass concentration(up to 200 g/L)and high condensate volume fraction(up to 20%)reached 84%.The dynamic surface tension and interfacial tension measured at the same temperature were used to analyze the influence of the diffusion rate and interfacial characteristics on the AE_(n)S foam,while the viscosity and liquid film thickness measurements reflected the mechanical strength and liquid-carrying capacity.In addition,transmission electron microscopy(TEM)revealed that AE_(2)S formed“dendritic”micellar aggregates at a high NaCl mass concentration,which significantly enhanced the viscosity and stability of the foam.The interactions among AE_(n)S,NaCl,and H2O were analyzed using molecular dynamics,and it was confirmed from a molecular mechanics perspective that a stable structure can form among the three,contributing to the foam stability.These findings demonstrate the significant potential of the AE_(2)S foam for gas well deliquification.展开更多
This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with ...This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with particular emphasis on the influence of different two-dimensional incident angles on phase delay behavior.Building upon the calibration of phase delay under normal incidence,a phase delay calibra-tion model was developed to account for variations in incident angle and driving voltage.A mathematical re-lationship was established between phase delay and the azimuth angle(α)and pitch angle(β).Experimental validation was conducted under three conditions:α=20°,β=0°;α=0°,β=20°;and an arbitrary angle whereα=5°,β=15°.The results demonstrated that the maximum average deviation between theoretical pre-dictions and experimental measurements did not exceed 0.059 rad.The proposed calibration method proved to be both accurate and practical.This approach offers robust support for LCVR parameter calibration and performance optimization in optical systems,particularly in polarization imaging applications.展开更多
Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were i...Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.展开更多
Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve inte...Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve intelligent functions like autonomous decisions and mechanical computation.However,current soft switches suffer from complex fabrication processes,limited performance,and a lack of multimodal control,which hinder their practical application and the realization of machine intelligence.Herein,by harnessing the unique self-pinch and self-healing effects of the gallium-based liquid metals(LMs),we describe a soft high-performance electric switch composed of an LM line encapsulated within an elastomer.Applying pressure to deform the LM switch can increase local current density,leading to the electromagnetic self-pinch effect for switching off.After releasing pressure,the LM can spontaneously heal with the elastic recovery of the elastomer for switching on.This LM switch shows comprehensive advantages,including a compact design(0.5 mm×1.5 mm×10 mm),good stretchability(100%),high on/off ratio(~10^(9)),rapid response time(<100 ms),and excellent durability(>12000 cycles).Moreover,the LM switches enable multiple control modes,including magnetic and optical stimulation,through the integration of responsive materials.We demonstrate various LM switch-enabled functional soft machines,such as an interactive flexible gripper,a self-oscillating soft crawler,and wearable logic gates.This work will open new avenues for the application of LM in intelligent soft machines and advanced wearable electronics.展开更多
This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization usin...This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization using high-speed camera imaging.The T-junction microchannel has a cross-sectional width of 0.6 mm and a total length of 27.3 mm.The solution of cyclohexane with 2%and 3%mass concentrations of sorbitan trioleate surfactant were used as the continuous phase,and water was used as the dispersed phase.Slug flow,characteristic of squeezing regime,were predominantly observed.The effects of liquid–liquid two-phase flow rate ratio,and dimensionless number on droplet size,and pressure drop were investigated.The squeezing regime was mapped for 0.0005≤Ca_(c)≤0.0052(capillary number)and 0.1≤q≤10(flow rate ratio).The pressure drops of slugs were in the range from 40 Pa to 200 Pa.The slug lengths were measured between 1 mm and 9 mm.A universal flow map dependent on Ca_(c)Re_(d)^(0.5) are projected to investigate the droplet formation behavior in T-junction microchannel.Correlation expressions are proposed to predict pressure drops and the slug lengths for liquid–liquid two-phase flow in a square T-junction microchannel,using dimensionless numbers such as flow rate ratio and capillary number.The result shows that large continuous phase flow rates facilitate smaller slugs,whereas higher dispersed phase flow rates result in longer shorts.展开更多
The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0....The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0.36,we studied the kagome-lattice t-J model using state-of-the-art density matrix renormalization group calculations.On the L_(y)=3 cylinder(Ly is the number of unit cells along the circumferential direction),we established a quantum phase diagram with an increasing doping level.In addition to the charge density wave states at lower doping levels,we found an emergent Fermi-liquid-like phase by melting the holon Wigner crystal at δ≈0.15,which is characterized by the suppression of charge density oscillation and power-law decay of various correlation functions.For a wider L_(y)=4 cylinder,the bond-dimension extrapolated correlation functions also support such a Fermi-liquid-like state,suggesting its stability with increasing system size.In a narrow doping range near δ=1/3 for the L_(y)=3 cylinder,we find a state with an exponential decay of the single-particle correlation,but the other correlation functions preserve the features in the Fermi-liquid-like phase,which may be a precursor of a superconducting state.Nevertheless,this peculiar state nearδ=1/3 disappears for the L_(y)=4 cylinder,implying a possible lattice-size dependence.Our results reveal quantum melting from a holon Wigner crystal to a Fermi-liquid-like state with increasing hole density and suggest a doping regime to explore superconductivity in future studies.展开更多
As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized fo...As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.展开更多
Despite the intrinsic durability of polymeric hole transport materials,poly-triarylamines(PTAA)-based inverted perovskite solar cells(PSCs)have lagged behind their counterparts in efficiency,primarily due to poor surf...Despite the intrinsic durability of polymeric hole transport materials,poly-triarylamines(PTAA)-based inverted perovskite solar cells(PSCs)have lagged behind their counterparts in efficiency,primarily due to poor surface wettability,insufficient interfacial contact,and unfavorable energy level alignment at the PTAA/perovskite interface.Here,we report a highly effective interfacial engineering strategy employing the ionic liquid 1,3-dimethylimidazolium dimethyl phosphate(DMIMPH)as a multifunctional interfacial modifier.The incorporation of DMIMPH improves PTAA wettability,promoting the growth of high-quality perovskite films with enhanced interfacial contact.Concurrently,DMIMPH effectively tunes the energy levels of PTAA,enhances its electrical conductivity,and passivates interfacial defects with more efficient hole extraction and charge transport.Moreover,its interaction with residual PbI_(2) modulates perovskite crystallization kinetics,yielding highly crystalline perovskite films with enlarged grain sizes,reduced PbI_(2) residue,and suppressed trap densities.As a result,PTAA-based p-i-n PSCs employing this approach achieve a record certified power conversion efficiency(PCE)of 24.52%,with a champion efficiency of 25.12%—the highest certified value for PTAA-based perovskite devices to date.Impressively,the DMIMPH-modified PSCs without encapsulation maintained 87.48%of their initial efficiency after 1600 h in air.This strategy offers an effective pathway for advancing the performance and stability of polymer-based inverted PSCs.展开更多
The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))an...The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))and Zn(BF_(4))_(2),the supramolecular gelatorβ-cyclodextrin(β-CD)was added,and then a gel electrolyte(CD-ILZE)for zinc-ion batteries was prepared through host-vip interaction betweenβ-CD and DMSO-ILZE electrolyte.The gel electrolyte has good conductivity between-30 and 80℃,which is found by fitting the Arrhenius equation that the gel electrolyte satisfies the liquid law within this temperature range.In addition,the supramolecular gel electrolyte can effectively decrease hydrogen evolution corrosion and the formation of zinc dendrites.Compared with the battery prepared by DMSO-ILZE electrolyte(about 1100 h),the prepared Zn||Zn battery exhibits a more stable cycle(over 2800 h)at a current density of 0.5 m A·cm^(-2).At 0.1 A·g^(-1),the prepared Zn||V_(2)O_(5)gel electrolyte cell has a capacity of 30 m Ah·g^(-1)and a capacity retention rate of 85.17%after more than 1500 cycles.The CD-ILZE supramolecular gel electrolyte can inhibit the formation of hydrogen evolution corrosion and zinc dendrites,and improve the cycling performance of the battery.展开更多
The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylh...The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.展开更多
Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection ...Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.展开更多
文摘Changing political and market conditions have disrupted energy security.European economies are planning to utilize their own resources of energy raw materials,including consideration of the advisability of returning abandoned coal resources to use.The research using the proposed methodology examined the impact of the ongoing mine closure processes on the potential ability to develop the remaining deposit.It was found that the greatest influence on the availability of unclosed shafts was the active concession to extract minerals from the deposit and the availability of unclosed main plant facilities.The assessment of the possibilities of coal resources management in the deposits of liquidated mines has not been the subject of extensive scientific research so far.The information obtained can be used as a reference point for detailed analysis and multi-criteria evaluation,after which the decision maker makes the decision.The method is designed for liquidated mines,but with certain modifications it can also be used by mining companies.
文摘The extended trading close(ETC)provides institutional investors an opportunity to trade at the closing price after the regular trading session(RTS)and disclosing the order imbalances to other market participants.ETCs exist in the Nasdaq,the SSE STAR,the SZSE ChiNext and the TWSE.To help a risk-averse institutional investor take advantage of the RTS and the ETC for liquidation,we develop a multistage dynamic programming model including the ETC,and derive recursive solutions for the multiple trading days scenario with closed-form solutions for the scenario with only two trading days.We also verify that the ETC is able to mitigate extreme price movements caused by fast liquidation,which is also a goal of the ETC set out by the SSE STAR and the SZSE ChiNext.Finally,we derive three results.First,an institutional investor can reduce execution costs after the introduction of the ETC.Second,a critical trading day exists,and to avoid prematurely revealing trading intentions,the investor should not trade in the ETC until such day.Third,even though the ETC orders submitted by the investor are unfilled,implementation of the ETC encourages the investor to change the liquidation strategy in the RTS,which reduces extreme price movements.In summary,the practical implications of this paper are that the investor should not trade during the ETC on the front few days to avoid prematurely revealing the investor’s trading intention by unfilled orders in the ETC and that introducing the ETC can reduce liquidation costs and extreme price movements.
文摘Doing business in China, while lucrative, can be a minefield to the uninitiated. This regular column by Deloitte will provide specific information to give businesspeople the tools they need to facilitate this process.
文摘We propose a forward approach to study the performance of liquidation strategies under sequential model parameter updates.The forward liquidation program consists of pasting forward in time and in a time-consistent fashion a series of optimal liquidation problems.They are triggered at the parameter shift instances,thus entirely eliminating model error,and last at most till the next parameter update.However,due to the nature of the model dynamics,solutions may cease to exist in finite time,even before the subsequent parameter update.Furthermore,forward liquidation strategies may never lead to full liquidation,even though they maximize the average utility of revenue and always preserve time-consistency.In juxtaposition,the traditional approach delivers full liquidation at the sought horizon but encounters considerable model error,generates value erosion,and is time-inconsistent.
基金the National Natural Science Foundation of China(Grant No.71671017).
文摘Based on the minimum loss probability criterion,this paper discusses the optimal strategy in multi-asset liquidation.First,we give the framework of the multi-asset liquidation problem and obtain the boundary conditions of the optimal liquidation strategy under the assumption of linear price impact functions and transform the multi-asset liquidation problem into the portfolio liquidation problem.On this basis,the asymptotic solution and numerical solution of the optimal liquidation strategy are obtained.Then,we simulate the trajectories of the optimal liquidation strategy and analyze the effects of parameters changes.
基金This research is supported by National Natural Science Foundation of China[grant number 71531010].
文摘This paper proposes a two-period model to examine which bankruptcy procedure is better for both the debtor and creditor when insolvency happens.Our theoretical model depicts how firm size,industry characteristics,equity structure,and debt structure determine firms’bankruptcy resolutions.Using a comprehensive sample of bankrupt firms in the United States,we verify the predictions of a theoretical model.In our study,we deploy Probit and Logit models to address the predictions in the theoretical framework and conduct a series of robustness checks with econometric methods like Propensity Score Matching to confirm the empirical results.This paper finds that firms with larger size have more chance to file for Chapter 11 reorganization when insolvency happens.We also find that firms in asset-heavy(asset-light)industries are more likely to be reorganized(liquidated)under U.S.bankruptcy code.
文摘In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.
文摘The laboratory established an efficient reversed-phase ultra-high-performance liquid chromatographyquadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS)qualitative method for screening more than 2000 kinds of risk substances(including local anesthetics,LAs)in cosmetics,which has been successfully applied in the analysis of actual samples.This work aims to develop a more convenient high performance liquid chromatography triple quadrupole mass spectrometry(HPLC-QQQ-MS/MS)method for the quantitative determination of LAs.Samples were ultrasonically extracted with methanol,separated on an Agilent Poroshell 120 EC-C18 column(2.1 mm×100 mm,2.7μm),and eluted with a gradient mobile phase consisting of 0.1%formic acid aqueous solution and methanol.Quantification was performed using the external standard method.The results show that all 23 LAs are effectively separated within 12 minutes,with good linearity in the corresponding concentration ranges and the correlation coefficients all greater than 0.99.The limits of detection(LOD)range from 0.0025 to 0.05μg/g,and the limits of quantification(LOQ)range from 0.01 to 0.1μg/g.The average recoveries of the 23 LAs in 5 blank cosmetic matrices are 80.68%-117.57%,with the relative standard deviations(RSDs)less than 5.98%.This method has good precision and high accuracy,and is suitable for the determination of LAs in 5 cosmetic matrices.
文摘A reversed-phase high-performance liquid chromatography(HPLC)method was developed for the direct determination of docosahexaenoic acid(DHA)in sturgeon caviar extract.The assay employed n-hexane extraction combined with gradient elution(ZORBAX SB-C18 column),with data collected using a diode array detector.The content was calculated by external standard method and validated against the national standard(GB 5009.168-2016).The study also measured DPPH free radical scavenging capacity and moisture retention rate across different DHA concentration groups.The results demonstrate that the proposed method exhibits excellent linearity(r=0.9997),with recovery rates ranging from 92.1% to 101.1% and relative standard deviations(RSD)of 2.23% to 3.92%.Compared to the national standard method,the relative deviation was 0.67% to 1.68%.At specific test concentrations,the high-DHA group shows significantly higher moisture retention(100.48%),hygroscopicity(100.85%),and DPPH scavenging efficiency(57.46%)than the low-DHA group(10.33%,11.76%,and 3.71%).The RP-HPLC method developed in this study simplifies DHA detection procedures with simple reagents and reliable results,making it suitable for rapid qualitative identification and quantitative analysis of target components in caviar extract quality control.The DPPH experiment further reveals the correlation between DHA content and antioxidant efficacy in sturgeon caviar extracts,providing scientific evidence for developing functional cosmetics.
文摘Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high condensate content,high temperature,and high salinity)often affect foaming agent performance.In this study,surfactants were screened using an airflow method that closely resembles field treatment method.Notably,alcohol ether sulfates(AE_(n)S)with various polyoxyethylene(EO)units demonstrated exceptional performance in terms of liquid unloading efficiency and foam stability.At 80℃,the unloading efficiency of AE_(n)S with two EO units(AE_(2)S)in a high NaCl mass concentration(up to 200 g/L)and high condensate volume fraction(up to 20%)reached 84%.The dynamic surface tension and interfacial tension measured at the same temperature were used to analyze the influence of the diffusion rate and interfacial characteristics on the AE_(n)S foam,while the viscosity and liquid film thickness measurements reflected the mechanical strength and liquid-carrying capacity.In addition,transmission electron microscopy(TEM)revealed that AE_(2)S formed“dendritic”micellar aggregates at a high NaCl mass concentration,which significantly enhanced the viscosity and stability of the foam.The interactions among AE_(n)S,NaCl,and H2O were analyzed using molecular dynamics,and it was confirmed from a molecular mechanics perspective that a stable structure can form among the three,contributing to the foam stability.These findings demonstrate the significant potential of the AE_(2)S foam for gas well deliquification.
文摘This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with particular emphasis on the influence of different two-dimensional incident angles on phase delay behavior.Building upon the calibration of phase delay under normal incidence,a phase delay calibra-tion model was developed to account for variations in incident angle and driving voltage.A mathematical re-lationship was established between phase delay and the azimuth angle(α)and pitch angle(β).Experimental validation was conducted under three conditions:α=20°,β=0°;α=0°,β=20°;and an arbitrary angle whereα=5°,β=15°.The results demonstrated that the maximum average deviation between theoretical pre-dictions and experimental measurements did not exceed 0.059 rad.The proposed calibration method proved to be both accurate and practical.This approach offers robust support for LCVR parameter calibration and performance optimization in optical systems,particularly in polarization imaging applications.
基金supported by the National Natural Science Foundation of China(22278272)Natural Science Foundation of Liaoning Province(2024-MS-129).
文摘Separation of 2-methylfuran(2-MF)and methanol(MeOH)azeotropes is a key challenge in biofuel production because of the efficiency and sustainability issues of conventional methods.In this study,ionic liquids(ILs)were introduced as green solvents for separation of 2-MF/MeOH through liquid–liquid equilibrium(LLE)experiment.Three ILs,namely 1-ethyl-3-methylimidazole dihydrogen phosphate([EMIM][H_(2)PO_(4)]),1-propyl-3-methylimidazole dihydrogen phosphate([PMIM][H_(2)PO_(4)])and 1-butyl-3-methylimidazole dihydrogen phosphate([BMIM][H_(2)PO_(4)]),were screened out from 425 candidates using the conductor-like screening model for real solvents(COSMO-RS).Then,the ternary LLE data of 2-MF(1)+MeOH(2)+ILs(3)were determined at 30℃ and 101.32 kPa.Results confirmed[EMIM][H_(2)PO_(4)]as the best performer,achieving a selectivity of 343.86 and a distribution coefficient of 36.66 for MeOH—significantly higher than[PMIM][H_(2)PO_(4)]and[BMIM][H_(2)PO_(4)].The accuracy of the LLE data was verified by Othmer–Tobias and Hand equations(R^(2)>0.90).The non-random two liquid model was used to correlate the experimental data(RMSD<2%).Besides,the combination of electrostatic surfaces potential,independent gradient model based on Hirshfeld partition,mean square displacement and radial distribution functions revealed strong electrostatic interactions between[H_(2)PO_(4)]^(–) and MeOH.Interaction energy analysis further emphasizes the mechanism of MeOH separation from a mixture of 2-MF and MeOH by ILs.This work provides a multiscale strategy for the separation of 2-MF and MeOH azeotropes,highlighting the potential of ILs to improve biofuel purification while reducing energy and environmental costs.
基金financial support from the Natural Science Foundation of Jiangsu Province(BK20220859)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)+2 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_0473)the SEU Innovation Capability Enhancement Plan for Doctoral Students(CXJH_SEU 24144)supported by Open Research Fund of State Key Laboratory of Analytical Chemistry for Life Science,School of Chemistry and Chemical Engineering,Nanjing University。
文摘Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve intelligent functions like autonomous decisions and mechanical computation.However,current soft switches suffer from complex fabrication processes,limited performance,and a lack of multimodal control,which hinder their practical application and the realization of machine intelligence.Herein,by harnessing the unique self-pinch and self-healing effects of the gallium-based liquid metals(LMs),we describe a soft high-performance electric switch composed of an LM line encapsulated within an elastomer.Applying pressure to deform the LM switch can increase local current density,leading to the electromagnetic self-pinch effect for switching off.After releasing pressure,the LM can spontaneously heal with the elastic recovery of the elastomer for switching on.This LM switch shows comprehensive advantages,including a compact design(0.5 mm×1.5 mm×10 mm),good stretchability(100%),high on/off ratio(~10^(9)),rapid response time(<100 ms),and excellent durability(>12000 cycles).Moreover,the LM switches enable multiple control modes,including magnetic and optical stimulation,through the integration of responsive materials.We demonstrate various LM switch-enabled functional soft machines,such as an interactive flexible gripper,a self-oscillating soft crawler,and wearable logic gates.This work will open new avenues for the application of LM in intelligent soft machines and advanced wearable electronics.
基金supports for this project from the National Natural Science Foundation of China(22378295).
文摘This study investigates the droplet formation for the liquid–liquid two-phase flow within a square T-junction microchannel through numerical simulation using volume of fluid method and experimental visualization using high-speed camera imaging.The T-junction microchannel has a cross-sectional width of 0.6 mm and a total length of 27.3 mm.The solution of cyclohexane with 2%and 3%mass concentrations of sorbitan trioleate surfactant were used as the continuous phase,and water was used as the dispersed phase.Slug flow,characteristic of squeezing regime,were predominantly observed.The effects of liquid–liquid two-phase flow rate ratio,and dimensionless number on droplet size,and pressure drop were investigated.The squeezing regime was mapped for 0.0005≤Ca_(c)≤0.0052(capillary number)and 0.1≤q≤10(flow rate ratio).The pressure drops of slugs were in the range from 40 Pa to 200 Pa.The slug lengths were measured between 1 mm and 9 mm.A universal flow map dependent on Ca_(c)Re_(d)^(0.5) are projected to investigate the droplet formation behavior in T-junction microchannel.Correlation expressions are proposed to predict pressure drops and the slug lengths for liquid–liquid two-phase flow in a square T-junction microchannel,using dimensionless numbers such as flow rate ratio and capillary number.The result shows that large continuous phase flow rates facilitate smaller slugs,whereas higher dispersed phase flow rates result in longer shorts.
基金supported by the National Natural Science Foundation of China (Grant Nos.12274014 and 12534009)the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2501006)+4 种基金the Special Project in Key Areas for Universities in Guangdong Province (Grant No.2023ZDZX3054)the Dongguan Key Laboratory of Artificial Intelligence Design for Advanced Materialssupported by the U.S.Department of Energy,Office of Basic Energy Sciences (Grant No.DE-FG02-06ER46305) for DMRG studies on unconventional superconductivitysupported by the SongShan Lake HPC Center (SSL-HPC) at Great Bay University (X.Y.J.and S.S.G.)supported in part by the US National Science Foundation (Grant No.DMR-2406524) (D.N.S.)。
文摘The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0.36,we studied the kagome-lattice t-J model using state-of-the-art density matrix renormalization group calculations.On the L_(y)=3 cylinder(Ly is the number of unit cells along the circumferential direction),we established a quantum phase diagram with an increasing doping level.In addition to the charge density wave states at lower doping levels,we found an emergent Fermi-liquid-like phase by melting the holon Wigner crystal at δ≈0.15,which is characterized by the suppression of charge density oscillation and power-law decay of various correlation functions.For a wider L_(y)=4 cylinder,the bond-dimension extrapolated correlation functions also support such a Fermi-liquid-like state,suggesting its stability with increasing system size.In a narrow doping range near δ=1/3 for the L_(y)=3 cylinder,we find a state with an exponential decay of the single-particle correlation,but the other correlation functions preserve the features in the Fermi-liquid-like phase,which may be a precursor of a superconducting state.Nevertheless,this peculiar state nearδ=1/3 disappears for the L_(y)=4 cylinder,implying a possible lattice-size dependence.Our results reveal quantum melting from a holon Wigner crystal to a Fermi-liquid-like state with increasing hole density and suggest a doping regime to explore superconductivity in future studies.
基金financially supported by the National Natural Science Foundation of China(Nos.22005226 and 52203124)Center for Carbon Neutral Chemistry,Institute of Chemistry,Chinese Academy of Sciences(No.CCNC-202402)+1 种基金the Basic and Advanced Research Project from Wuhan Science and Technology Bureau(No.2022013988065201)Hubei Integrative Technology and Innovation Center for Advanced Fiberous Materials,project(No.XC2024G3013)。
文摘As the global textile industry has accelerated its transition to a circular economy,iterative innovation in regenerated cellulose fibers has become a key industry focus.With viscose fiber having been industrialized for over a century and lyocell fiber gaining market recognition because of its environmentally friendly process,which is the next regenerated cellulose fiber.Herein,ionic liquids with low vapor pressure,nonflammability,relatively simple recovery,and high dissolution efficiency were used to fabricate regenerated cellulose fibers.The viscose and lyocell properties of the fibers were systematically compared,including microscopic morphology,dyeing behavior,fibrillation resistance,mechanical properties,yarn-forming capacity,and fabric performance.The ionic liquid(IL)fiber exhibited a smooth surface and circular cross-section,with the highest tensile strength,moderate dyeing and fibrillation properties,and similar spinning and weaving performance.This work can provide a reference for the commercial application of regenerated cellulose fibers fabricated from ionic liquid.
基金supported by the Research Projects of the Department of Education of Guangdong Province 2024ZDZX3079The financial support from the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011677)+4 种基金the Scientific and Technical Innovation Council of Shenzhen(20220812165832002)the Research Projects of Department of Education of Guangdong Province-2023GCZX015the Innovation Team Project of Guangdong(2022KCXTD055)the China Postdoctoral Science Foundation(Certificate Number:2024M763441)is gratefully acknowledgedsupported by the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20250031 and Research Projects of the Department of Education of Guangdong Province 2023GCZX015。
文摘Despite the intrinsic durability of polymeric hole transport materials,poly-triarylamines(PTAA)-based inverted perovskite solar cells(PSCs)have lagged behind their counterparts in efficiency,primarily due to poor surface wettability,insufficient interfacial contact,and unfavorable energy level alignment at the PTAA/perovskite interface.Here,we report a highly effective interfacial engineering strategy employing the ionic liquid 1,3-dimethylimidazolium dimethyl phosphate(DMIMPH)as a multifunctional interfacial modifier.The incorporation of DMIMPH improves PTAA wettability,promoting the growth of high-quality perovskite films with enhanced interfacial contact.Concurrently,DMIMPH effectively tunes the energy levels of PTAA,enhances its electrical conductivity,and passivates interfacial defects with more efficient hole extraction and charge transport.Moreover,its interaction with residual PbI_(2) modulates perovskite crystallization kinetics,yielding highly crystalline perovskite films with enlarged grain sizes,reduced PbI_(2) residue,and suppressed trap densities.As a result,PTAA-based p-i-n PSCs employing this approach achieve a record certified power conversion efficiency(PCE)of 24.52%,with a champion efficiency of 25.12%—the highest certified value for PTAA-based perovskite devices to date.Impressively,the DMIMPH-modified PSCs without encapsulation maintained 87.48%of their initial efficiency after 1600 h in air.This strategy offers an effective pathway for advancing the performance and stability of polymer-based inverted PSCs.
文摘The preparation of ionic liquid gel electrolyte can reduce the occurrence of side effects and extend battery life.In the DMSO-ILZE electrolyte composed of DMSO,1-ethyl-3-methylimidazole tetrafluoroborate(EMIMBF_(4))and Zn(BF_(4))_(2),the supramolecular gelatorβ-cyclodextrin(β-CD)was added,and then a gel electrolyte(CD-ILZE)for zinc-ion batteries was prepared through host-vip interaction betweenβ-CD and DMSO-ILZE electrolyte.The gel electrolyte has good conductivity between-30 and 80℃,which is found by fitting the Arrhenius equation that the gel electrolyte satisfies the liquid law within this temperature range.In addition,the supramolecular gel electrolyte can effectively decrease hydrogen evolution corrosion and the formation of zinc dendrites.Compared with the battery prepared by DMSO-ILZE electrolyte(about 1100 h),the prepared Zn||Zn battery exhibits a more stable cycle(over 2800 h)at a current density of 0.5 m A·cm^(-2).At 0.1 A·g^(-1),the prepared Zn||V_(2)O_(5)gel electrolyte cell has a capacity of 30 m Ah·g^(-1)and a capacity retention rate of 85.17%after more than 1500 cycles.The CD-ILZE supramolecular gel electrolyte can inhibit the formation of hydrogen evolution corrosion and zinc dendrites,and improve the cycling performance of the battery.
基金Project supported by the National Key Research and Development Program of China(2022YFC2905800)National Natural Science Foundation of China(52374276,52274269)+2 种基金Yunnan Fundamental Re search Projects(202401AS070051)the Natural Science Foundation of Hubei Province of China(2024AFD123)Young Elite Scientists Sponsorship Program by CAST(YESS20200276)。
文摘The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.
文摘Pediatric cancers are particularly significant due to their uncommon occurrence in children,driven by a variety of underlying factors.Because of their distinct molecular and genetic makeup,which makes early detection challenging,they are linked to problems.Diagnostic methods like imaging and tissue biopsy are only effective when the tumor has reached a size that can be identified.The liquid biopsy technique,the least intrusive and most convenient diagnostic method,is the subject of this review.It focuses on the significance of single cell analysis in examining uncommon cancer types.The many biomarkers found in bodily fluids and the cancer types they are linked to in children have been assessed,as has the potential route towards early detection and cancer recurrence forecasting.Combining the single cell liquid biopsy with the newest technologies,such as computational and multi-omics approaches,which have improved the efficiency of processing massive and unique genetic data,appears promising.This article discusses on a number of case reports for uncommon pediatric malignancies,such as Neuroblastoma,Medulloblastoma,Wilms Tumor,Rhabdomyosarcoma,Ewing Sarcoma,and Retinoblastoma,as well as their liquid biopsy profiles.Furthermore,the findings raise ethical questions regarding the therapeutic application of the technology as well as possible difficulties related to clinical translation.The likelihood that this single cell liquid biopsy will be clinically validated and eventually used as a routine diagnostic tool for uncommon pediatric cancers will rise with the realistic approach to sensitivity monitoring,specificity upgrading,and optimization.
