Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been construc...Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.展开更多
Stress granules are membraneless organelles that serve as a protective cellular response to external stressors by sequestering non-translating messenger RNAs(mRNAs)and regulating protein synthesis.Stress granules form...Stress granules are membraneless organelles that serve as a protective cellular response to external stressors by sequestering non-translating messenger RNAs(mRNAs)and regulating protein synthesis.Stress granules formation mechanism is conserved across species,from yeast to mammals,and they play a critical role in minimizing cellular damage during stress.Composed of heterogeneous ribonucleoprotein complexes,stress granules are enriched not only in mRNAs but also in noncoding RNAs and various proteins,including translation initiation factors and RNA-binding proteins.Genetic mutations affecting stress granule assembly and disassembly can lead to abnormal stress granule accumulation,contributing to the progression of several diseases.Recent research indicates that stress granule dynamics are pivotal in determining their physiological and pathological functions,with acute stress granule formation offering protection and chronic stress granule accumulation being detrimental.This review focuses on the multifaceted roles of stress granules under diverse physiological conditions,such as regulation of mRNA transport,mRNA translation,apoptosis,germ cell development,phase separation processes that govern stress granule formation,and their emerging implications in pathophysiological scenarios,such as viral infections,cancer,neurodevelopmental disorders,neurodegeneration,and neuronal trauma.展开更多
MPHPB was prepared from melamine,phenylphosphonic acid and boric acid,and its flame retardant effect in PE was investigated.Compared to the intermediate product(melamine phenyl hypophosphite(MPHP)),the residual char i...MPHPB was prepared from melamine,phenylphosphonic acid and boric acid,and its flame retardant effect in PE was investigated.Compared to the intermediate product(melamine phenyl hypophosphite(MPHP)),the residual char increased from 17.9% of MPHP to 41.2% of MPHPB at 800℃.The limiting oxygen index(LOI)of PE/20%MPHPB is 23.6%,which reaches V-0 rating.After the addition of 20%MPHPB,the total heat release(THR),peak heat release rate(pK-HRR),and average effective thermal combustion rates(av-EHC)of PE decreased.Additionally,characterizations including the pyrolysis gas chromatography-mass spectrometry(Py-GC-MS),scanning electron microscopy(SEM),raman spectroscopy test(LRS)and fourier transform infrared(FT-IR)were taken to investigate the flame retardant mechanism,and the results show that MPHPB plays roles in both gas and condensed phases.展开更多
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under...(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.展开更多
Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dep...Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dependent on their impurity levels,and the lack of high-purity Mg,along with efficient purification method,has posed significant challenge to its widespread industrial adoption.This study investigates the impurity behavior in Mg ingots during the vacuum gasification purification process.Through the analysis of binary phase diagrams,iron(Fe)-based foam material was selected for the filtration and purification of Mg vapor in a vacuum tube furnace.A novel approach combining vacuum gasification,vapor purification,and directional condensation is proposed.The effect of filter pore sizes and filtration temperatures on the efficacy of impurity removal was evaluated.Experimental results demonstrate that Fe-based foam with a pore size of 60 ppi,at a filtration temperature of 773 K,effectively removes impurities such as calcium(Ca),potassium(K),sodium(Na),manganese(Mn),silicon(Si),aluminum(Al),and various oxides,sulfides,and chlorides from the vapor phase.Consequently,high-purity Mg with a purity level exceeding 5N3 was obtained in the condensation zone.展开更多
1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2...1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2 gas field,150 km off the southeast coast of Hainan Island,China.It is a semi-submersible platform(Fig.1)with a displacement of 101 thousand tonnes and an operational draft of 35 to 40 m.The platform is permanently moored in 1422 m water by 16 chain-polyester-chain mooring lines in a 4×4 pattern,and six steel catenary risers(SCRs)are attached to the platform.It is the world’s first and only semi-submersible platform with the function of condensate storage,so it can be regarded as a floating production storage and offloading(FPSO)unit.With the ability to produce 3 billion m3 of natural gas each year(enough for over 10 million families),the Deep Sea No.1 energy station is a key step toward China’s energy independence.The LS17-2 gas field,where the Deep Sea No.1 energy station is located,was discovered in 2014.Plans for its development were made in 2015,followed by research and a preliminary design.Deep Sea No.1 went into operation on June 25,2021,and will operate onsite continuously without dry-docking for 30 years.展开更多
We classify condensable𝐸E_(2)-algebras in a modular tensor category C up to 2-Morita equivalence.Physically,this classification provides an explicit criterion to determine when distinct condensable𝐸E_(...We classify condensable𝐸E_(2)-algebras in a modular tensor category C up to 2-Morita equivalence.Physically,this classification provides an explicit criterion to determine when distinct condensable𝐸E_(2)-algebras yield the same condensed topological phase under a two-dimensional anyon condensation process.The relations between different condensable algebras can be translated into their module categories,interpreted physically as gapped domain walls in topological orders.As concrete examples,we interpret the categories of quantum doubles of finite groups and examples beyond group symmetries.Our framework fully elucidates the interplay among condensable𝐸E_(1)-algebras in C,condensable𝐸E_(2)-algebras in C up to 2-Morita equivalence,and Lagrangian algebras in C⊠C.展开更多
Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been ...Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been demonstrated in polariton condensates in III-V photonic crystal microcavities by condensing into a topological bound state in the continuum,offering a new light-matter hybrid platform for exploring such quantum phase.In this work,we propose a theoretical scheme for realizing room-temperature supersolidity based on halide perovskite exciton polaritons operating in the optical parametric oscillation regime.By employing a waveguide microcavity geometry,we confine polariton scattering direction in reciprocal space,enabling controlled momentum selection.Leveraging the intrinsic nonlinear interactions among polaritons,we theoretically demonstrate the spontaneous breaking of both continuous translational symmetry and global phase symmetry,i.e.,the evidence of supersolidity.Furthermore,we identify a tunable phase transition sequence in our system:from a Bose-Einstein condensate to a supersolid phase,and ultimately to an insulating phase,as the nonlinear interaction strength increases.展开更多
Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often ...Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often hindered by the dual challenges of retrograde condensation and water invasion,which can markedly reduce recovery factors.CO_(2) injection offers a promising solution by alleviating condensate blockage,suppressing water influx,and simultaneously enabling geological CO_(2) storage.Accordingly,research on optimizing CO_(2) injection to mitigate formation damage is critical for the efficient development and management of edge-and bottom-water condensate gas reservoirs.In this study,a long-core displacement mechanism model was constructed using CMG-GEMTM andWinPropTM.The model simulates reservoir depletion from initial conditions(41.2 MPa,102.5℃)to the current reservoir pressure(13.5 MPa),followed by gas injection.It was then upscaled to the edge-and bottom-water reservoir scale to capture complex fluid phase behavior,enabling a multi-factor coupled optimization of CO_(2) injection strategies.Model reliability was verified through comparison with core experimental results.Subsequently,the effects of geological parameters(e.g.,reservoir permeability and rhythmic heterogeneity)and engineering parameters(e.g.,injection pressure and rate)on reservoir performance were systematically evaluated.The results indicate that appropriate target zone selection and optimization of injection pressure and rate—avoiding formation fracturing and preventing gas channeling—can substantially improve reservoir development outcomes.Applying this approach to the K Gas Reservoir,the optimal strategy involved injecting CO_(2) at a rate of 5×10^(4) m^(3)/d,restoring pressure to 22.5 MPa in a composite rhythmic reservoir with an average permeability of 10 mD.This scheme increased the condensate oil recovery factor by 18.7 percentage points(from 43.9%to 60.9%)while reducing the water-cut rise rate by approximately 34%.展开更多
The active cooling technology of endothermic hydrocarbon fuels is a key way to solve the thermal protection of high-speed aircraft engines,but the condensation coking problem during engine shutdown is a bottleneck tha...The active cooling technology of endothermic hydrocarbon fuels is a key way to solve the thermal protection of high-speed aircraft engines,but the condensation coking problem during engine shutdown is a bottleneck that affects the reusability of aircraft.In this study,a self-designed apparatus was used to separately analyze the condensation coking during the fuel cooling process,and the coking characteristics under different temperature conditions were obtained.The condensation coking mechanism of fuel during cooling process was proposed based on the changes in physical properties of coking precursors obtained by the group contribution method.When the temperature drops to 300℃,not only the gas yield and conversion increase to 71.42% and 89.75% respectively,but the coke mass on the inner surface of the tube also significantly increases from 0.39 to 1.92 mg.Meanwhile,as the temperature further decreases,the morphology of coke gradually transforms into amorphous carbon with a higher degree of graphitization.During the cooling process,due to the liquefaction of coking precursors,their physical properties such as viscosity,density,and saturated vapor pressure undergo sudden changes at 300℃,leading to enhanced intermolecular physical interactions and promoting the physical aggregation of coking precursor molecules,which are deposited on the inner wall of the tube.This work provides a theoretical basis for the subsequent study of condensation coking mechanisms and inhibition methods.展开更多
Compared with Pidgeon process,the relative vacuum continuous magnesium smelting process reduces the ratio of material to magnesium by changing raw materials and the direct reduction after calcination of prefabricated ...Compared with Pidgeon process,the relative vacuum continuous magnesium smelting process reduces the ratio of material to magnesium by changing raw materials and the direct reduction after calcination of prefabricated pellets,so that the energy consumption per ton of magnesium produced is reduced by 30∼40%,and the carbon emission is reduced by 43∼52%,breaking through the vacuum conditions to achieve continuous production.However,in the process of industrialization,it was found that the magnesium yield in the condenser was low.Therefore,this paper constructs a condenser model of relative vacuum continuous magnesium refining process,and comprehensively analyzes the condensation mechanism of magnesium vapor through simulation and experiment.It is found that the dynamic characteristics of magnesium vapor condensation is an important index to measure its continuity.Under the condition offlowing argon as the protective gas,when the condensation plate spacing is 10 cm,the surface roughness amplitude variance is 2,and the carrier gasflow rate is 20×10^(-3) m/s,the magnesium vapor has a better condensation effect,and the condensation efficiency formula is derived.展开更多
Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that ...Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.展开更多
Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological inn...Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological innovations.Currently,exploring facile micro/nanofabrication approaches to create high-efficiency CHT surfaces has been one of research hotspots.In this work,we propose and demonstrate a type of new superwettability hybrid surface for high-efficiency CHT,which consists of superhydrophobic nanoneedle arrays and triangularly-patterned superhydrophilic microdots(SMDs).Such hybrid surface can be fabricated by the facile growth of densely-packed ZnO nanoneedles on the Zn-electroplated copper surface followed by fluorosilane modification and mask-assisted photodegradation.Through regulating the diameters and interspaces of SMDs,we obtain the optimized triangularly-patterned hybrid surface,which shows 42.7%higher CHT coefficient than the squarely-patterned hybrid surface and 58.5%higher CHT coefficient than the superhydrophobic surface.The key of such hybrid surface design is to considerably increase CHT coefficient brought about by SMD-triggered drop sweeping at the cost of slightly reducing heat transfer area of superhydrophobic functional zone for drop jumping.Such new strategy helps develop advanced CHT surfaces for high-efficiency electronic cooling and energy utilization.展开更多
The self-condensation of n-butanal is an important reaction for carbon-chain extension in the commercial production of 2-ethylhexanol.Moreover,aldol condensation is one of the important reactions for the synthesis of ...The self-condensation of n-butanal is an important reaction for carbon-chain extension in the commercial production of 2-ethylhexanol.Moreover,aldol condensation is one of the important reactions for the synthesis of valuable organic chemicals or transportation fuels from biomass-derived platform compounds.So the investigation of the self-condensation of n-butanal is of significance in both academia and industry.This contribution reviewed the catalytic performance of heterogeneous catalysts in the self-condensation of n-butanal and the related reaction mechanism,network,and kinetics.The purpose of this review is to dedicate some help for further development of environmentally friendly catalysts and for a thorough comprehension of aldol condensation.展开更多
The production processes for Si and FeSi have traditionally been considered slag-free.However,recent excavations have revealed significant accumulation of CaO–SiO_(2)–Al_(2)O_(3)slag within the furnaces.This accumul...The production processes for Si and FeSi have traditionally been considered slag-free.However,recent excavations have revealed significant accumulation of CaO–SiO_(2)–Al_(2)O_(3)slag within the furnaces.This accumulation can obstruct the flow of materials and gases,resulting in lower metal yield and higher energy consumption.The main objective of the current work is to enhance our understanding of slag formation during Si and FeSi production.We investigate slag formation through the dissolution of limestone and iron oxide in quartz and condensate,focusing on the reactions between these materials at a gram scale.Our findings indicate that most slag reaches equilibrium relatively quickly at temperatures starting from 1673 K.Notably,slag formation starts at lower temperature when the iron source is present (1573 K) compared to when only CaO is involved (1673 K).The minor elements tend to accumulate at quartz grain boundaries prior to slag formation.Furthermore,the slag produced from condensate contains less SiO_(2)than that generated from quartz with limestone.The type of quartz source and SiO_(2)phase appears to have little influence on slag formation.Good wettability is a significant factor in reaction between quartz and slag.FactSage calculations indicates that the viscosity of the slag ranges from 0.02 to 14.4 Pa·s under furnace conditions,comparable to the viscosity of honey or motor oil at room temperature.展开更多
Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in ...Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in Ⅲ-Ⅴ semiconductors at liquid helium temperatures.However,the complex fabrication of these microcavities and operating temperatures limit their room-temperature practical application.Here,we experimentally realize room-temperature exciton-polariton condensation and polaritonic lasing in a CsPbBr_(3)perovskite planar microcavity fabricated by the pressing process.Angleresolved photoluminescence spectra demonstrate the strong light-matter coupling and the formation of exciton-polaritons in such a pressed microcavity.Above the critical threshold,mass polaritons accumulating at the bottom of dispersion lead to a narrow emission linewidth and pronounced blueshift,further reinforcing the Bose-Einstein condensation and polaritonic lasing in this system.Our results offer a feasible and effective approach to investigate exciton-polariton condensation and polariton lasing at room temperature.展开更多
Formamide condensation with Ni can generate the N–C structure,widely recognized as an efficient catalyst for electrocatalytic CO_(2) reduction reaction(CO_(2)RR).To improve the utilization efficiency of Ni atoms,we i...Formamide condensation with Ni can generate the N–C structure,widely recognized as an efficient catalyst for electrocatalytic CO_(2) reduction reaction(CO_(2)RR).To improve the utilization efficiency of Ni atoms,we introduced metal oxides as substrates to modulate the growth of a formamide-Ni(FA-Ni)condensate.FA-Ni@TiO_(2) demonstrated 2.8 times higher partial CO current density and Ni turnover frequency than FA-Ni,which were also higher than those of other FA-Ni@metal oxides,including ZrO_(2),Al_(2)O_(3),Fe_(2)O_(3),and ZnO.The improved performance of CO_(2)RR can be attributed to the Ni content exposed on FA-Ni@TiO_(2) being twice that of the raw FA-Ni condensate.The Fourier transform infrared results suggested that formamide was adsorbed on TiO_(2) via the-CHO group,exposing-NH_(2) for potential interaction with Ni.As a result,Ni atoms were predispersed on the TiO_(2) surface.By contrast,the dispersion of Ni atoms was not enhanced by other metal oxides,such as Al_(2)O_(3),Fe_(2)O_(3),and ZnO,owing to the robust acidity of their surface sites.These metal oxides adsorbed formamide via-NH_(2),leading to the absence of extra-NH_(2) available for binding to Ni atoms.This study provides new insights into the development of appropriate substrates for single-atom catalysts.展开更多
There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct...There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct constant volume depletion experiments and investigate the microscopic mechanisms of condensate gas recovery.The aim of the experiments was to reveal the phase-behavior differences between bulk-phase gas and gas contained in porous media.The results revealed that condensate oil recovery in microfluidics experiments was higher than that in PVT cell tests,and nonuniform condensation and evaporation were exclusively observed in the microfluidics experiments.Furthermore,lower pore connectivity resulted in higher depletion recovery,while more developed fractures led to reduced recovery.Specifically,the chip with fewer fractures achieved the highest recovery(71.15%),whereas the highly fractured chip exhibited the lowest recovery(56.11%).These findings demonstrate that oil saturation during the process of constant volume depletion(CVD)of gas condensate within porous media is lower than that observed in the PVT cell,thus providing experimental evidence for optimizing condensate gas development in field applications.展开更多
Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder ...Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder and expert knowledge to achieve the early warning and causal analysis of condensate water quality abnormalities.An early warning model using an autoencoder model is built based on the historical data affecting the condensate water quality.Next,an analytical model of condensate water quality abnormalities was then developed by combining expert knowledge and trend test algorithms.Two different datasets were used to test the proposed model,respectively.The accuracy of the autoencoder model in the short-period test set is 88.83%,which shows that the early warning model can accurately analyze the condensate water quality data and achieve the purpose of early warning.For the long-time period test set,the model can correctly identify each abnormality and simultaneously indicates the cause of the abnormal condensate water quality.The proposed model can correctly identify abnormal working conditions and it is applicable to other thermal power plants.展开更多
We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated...We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated atom-atom interaction is equivalent to being constrained by a nonlinear optical lattice.Theoretical analyses show the existence of a steady atomic current in the BEC with a spatially varying phase.Under perturbative conditions,the Melnikov chaos criteria of BECs with a spatially varying phase and a constant one are theoretically obtained,respectively.When the perturbative conditions cannot be satisfied,for a repulsive BEC with a spatially varying phase,numerical simulations demonstrate that changing the initial condition can eliminate the chaotic spatial structure and then the system transitions into a biperiodic spatial structure.Increasing the chemical potential can result in a transition from the biperiodic spatial structure to a single-periodic spatial structure.For an attractive BEC with a spatially varying phase,numerical simulations show that decreasing the chemical potential can lead to a high atomic density,but when the wave number of the laser inducing the optical Feshbach resonance exceeds a critical value,the atomic density falls back to a finite range.Regardless of whether the BEC has a spatially varying phase or a constant one,modulating the laser wave number can effectively suppress the chaotic spatial structure in the BEC and then force it into a regular spatial structure.展开更多
文摘Three zinc(Ⅱ),nickel(Ⅱ),and cadmium(Ⅱ)complexes,namely[Zn(μ-Htpta)(py)_(2)]n(1),[Ni(H_(2)biim)2(H_(2)O)2][Ni(tpta)(H_(2)biim)2(H_(2)O)]2·3H_(2)O(2),and[Cd_(3)(μ4-tpta)2(μ-dpe)_(3)]_(n)(3),have been constructed hydrothermally at 160℃ using H_(3)tpta([1,1':3',1″-terphenyl]-4,4',5'-tricarboxylic acid),py(pyridine),H_(2)biim(2,2'-biimidazole),dpe(1,2-di(4-pyridyl)ethylene),and zinc,nickel and cadmium chlorides,resulting in the formation of stable crystalline solids which were subsequently analyzed using infrared spectroscopy,element analysis,thermogravimetric analysis,as well as structural analyses conducted via single-crystal X-ray diffraction.The findings from these single-crystal Xray diffraction studies indicate that complexes 1-3 form crystals within the monoclinic system P2_(1)/c space group(1)or triclinic system P1 space group(2 and 3),and possess 1D,0D,and 3D structures,respectively.Complex 1 demonstrated substantial catalytic efficiency and excellent reusability as a heterogeneous catalyst in the reaction of Knoevenagel condensation under ambient temperature conditions.In addition,complex 1 also showcased notable anti-wear performance when used in polyalphaolefin synthetic lubricants.CCDC:2449810,1;2449811,2;2449812,3.
基金supported by a grant from the Merkin Peripheral Neuropathy and Nerve Regeneration Center(to PKS)the Rutgers University Startup Fund(to PKS).
文摘Stress granules are membraneless organelles that serve as a protective cellular response to external stressors by sequestering non-translating messenger RNAs(mRNAs)and regulating protein synthesis.Stress granules formation mechanism is conserved across species,from yeast to mammals,and they play a critical role in minimizing cellular damage during stress.Composed of heterogeneous ribonucleoprotein complexes,stress granules are enriched not only in mRNAs but also in noncoding RNAs and various proteins,including translation initiation factors and RNA-binding proteins.Genetic mutations affecting stress granule assembly and disassembly can lead to abnormal stress granule accumulation,contributing to the progression of several diseases.Recent research indicates that stress granule dynamics are pivotal in determining their physiological and pathological functions,with acute stress granule formation offering protection and chronic stress granule accumulation being detrimental.This review focuses on the multifaceted roles of stress granules under diverse physiological conditions,such as regulation of mRNA transport,mRNA translation,apoptosis,germ cell development,phase separation processes that govern stress granule formation,and their emerging implications in pathophysiological scenarios,such as viral infections,cancer,neurodevelopmental disorders,neurodegeneration,and neuronal trauma.
基金Funded by the Natural Science Foundation of Guangdong(Nos.2014A030313241,2014B090901068,and 2016A010103003)。
文摘MPHPB was prepared from melamine,phenylphosphonic acid and boric acid,and its flame retardant effect in PE was investigated.Compared to the intermediate product(melamine phenyl hypophosphite(MPHP)),the residual char increased from 17.9% of MPHP to 41.2% of MPHPB at 800℃.The limiting oxygen index(LOI)of PE/20%MPHPB is 23.6%,which reaches V-0 rating.After the addition of 20%MPHPB,the total heat release(THR),peak heat release rate(pK-HRR),and average effective thermal combustion rates(av-EHC)of PE decreased.Additionally,characterizations including the pyrolysis gas chromatography-mass spectrometry(Py-GC-MS),scanning electron microscopy(SEM),raman spectroscopy test(LRS)and fourier transform infrared(FT-IR)were taken to investigate the flame retardant mechanism,and the results show that MPHPB plays roles in both gas and condensed phases.
文摘(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.
基金supported by the Yunnan Province Nonferrous Metal Vacuum Metallurgy Top Team[No.202305AS350012]。
文摘Magnesium(Mg),as one of the most abundant elements in earth's crust,is the lightest structural metal with extensive applications across various industries.However,the performance of Mg-based products is highly dependent on their impurity levels,and the lack of high-purity Mg,along with efficient purification method,has posed significant challenge to its widespread industrial adoption.This study investigates the impurity behavior in Mg ingots during the vacuum gasification purification process.Through the analysis of binary phase diagrams,iron(Fe)-based foam material was selected for the filtration and purification of Mg vapor in a vacuum tube furnace.A novel approach combining vacuum gasification,vapor purification,and directional condensation is proposed.The effect of filter pore sizes and filtration temperatures on the efficacy of impurity removal was evaluated.Experimental results demonstrate that Fe-based foam with a pore size of 60 ppi,at a filtration temperature of 773 K,effectively removes impurities such as calcium(Ca),potassium(K),sodium(Na),manganese(Mn),silicon(Si),aluminum(Al),and various oxides,sulfides,and chlorides from the vapor phase.Consequently,high-purity Mg with a purity level exceeding 5N3 was obtained in the condensation zone.
文摘1.Introduction As China’s first floating production platform in ultra-deepwater,the“Deep Sea No.1”energy station is a milestone in China’s deepwater resource utilization.The energy station is located in the LS17-2 gas field,150 km off the southeast coast of Hainan Island,China.It is a semi-submersible platform(Fig.1)with a displacement of 101 thousand tonnes and an operational draft of 35 to 40 m.The platform is permanently moored in 1422 m water by 16 chain-polyester-chain mooring lines in a 4×4 pattern,and six steel catenary risers(SCRs)are attached to the platform.It is the world’s first and only semi-submersible platform with the function of condensate storage,so it can be regarded as a floating production storage and offloading(FPSO)unit.With the ability to produce 3 billion m3 of natural gas each year(enough for over 10 million families),the Deep Sea No.1 energy station is a key step toward China’s energy independence.The LS17-2 gas field,where the Deep Sea No.1 energy station is located,was discovered in 2014.Plans for its development were made in 2015,followed by research and a preliminary design.Deep Sea No.1 went into operation on June 25,2021,and will operate onsite continuously without dry-docking for 30 years.
基金supported by Research Grants Council(RGC),University Grants Committee(UGC)of Hong Kong(ECS No.24304722)。
文摘We classify condensable𝐸E_(2)-algebras in a modular tensor category C up to 2-Morita equivalence.Physically,this classification provides an explicit criterion to determine when distinct condensable𝐸E_(2)-algebras yield the same condensed topological phase under a two-dimensional anyon condensation process.The relations between different condensable algebras can be translated into their module categories,interpreted physically as gapped domain walls in topological orders.As concrete examples,we interpret the categories of quantum doubles of finite groups and examples beyond group symmetries.Our framework fully elucidates the interplay among condensable𝐸E_(1)-algebras in C,condensable𝐸E_(2)-algebras in C up to 2-Morita equivalence,and Lagrangian algebras in C⊠C.
基金supported by the National Natural Science Foundation of China(Grant No.12434011 obtained by Q X)the China Postdoctoral Science Foundation(Grant No.Y24PJ2425214 obtained by L T).
文摘Supersolidity is a counterintuitive quantum phase of matter where the long-range spatial order of a solid coexists with the frictionless flow characteristic of a superfluid.Recently,evidence of supersolidity has been demonstrated in polariton condensates in III-V photonic crystal microcavities by condensing into a topological bound state in the continuum,offering a new light-matter hybrid platform for exploring such quantum phase.In this work,we propose a theoretical scheme for realizing room-temperature supersolidity based on halide perovskite exciton polaritons operating in the optical parametric oscillation regime.By employing a waveguide microcavity geometry,we confine polariton scattering direction in reciprocal space,enabling controlled momentum selection.Leveraging the intrinsic nonlinear interactions among polaritons,we theoretically demonstrate the spontaneous breaking of both continuous translational symmetry and global phase symmetry,i.e.,the evidence of supersolidity.Furthermore,we identify a tunable phase transition sequence in our system:from a Bose-Einstein condensate to a supersolid phase,and ultimately to an insulating phase,as the nonlinear interaction strength increases.
基金supported by the National Natural Science Foundation of China(No.52474047).
文摘Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often hindered by the dual challenges of retrograde condensation and water invasion,which can markedly reduce recovery factors.CO_(2) injection offers a promising solution by alleviating condensate blockage,suppressing water influx,and simultaneously enabling geological CO_(2) storage.Accordingly,research on optimizing CO_(2) injection to mitigate formation damage is critical for the efficient development and management of edge-and bottom-water condensate gas reservoirs.In this study,a long-core displacement mechanism model was constructed using CMG-GEMTM andWinPropTM.The model simulates reservoir depletion from initial conditions(41.2 MPa,102.5℃)to the current reservoir pressure(13.5 MPa),followed by gas injection.It was then upscaled to the edge-and bottom-water reservoir scale to capture complex fluid phase behavior,enabling a multi-factor coupled optimization of CO_(2) injection strategies.Model reliability was verified through comparison with core experimental results.Subsequently,the effects of geological parameters(e.g.,reservoir permeability and rhythmic heterogeneity)and engineering parameters(e.g.,injection pressure and rate)on reservoir performance were systematically evaluated.The results indicate that appropriate target zone selection and optimization of injection pressure and rate—avoiding formation fracturing and preventing gas channeling—can substantially improve reservoir development outcomes.Applying this approach to the K Gas Reservoir,the optimal strategy involved injecting CO_(2) at a rate of 5×10^(4) m^(3)/d,restoring pressure to 22.5 MPa in a composite rhythmic reservoir with an average permeability of 10 mD.This scheme increased the condensate oil recovery factor by 18.7 percentage points(from 43.9%to 60.9%)while reducing the water-cut rise rate by approximately 34%.
基金support from the National Natural Science Foundation of China (22308233,92060101)the Natural Science Foundation of Sichuan Province of China (2024NSFSC1162)+1 种基金the Source of Origin Project of Beijing Power Machinery Research Institutethe Sichuan Province Science Fund for Distinguished Young Scholars (2021JDJQ0011)。
文摘The active cooling technology of endothermic hydrocarbon fuels is a key way to solve the thermal protection of high-speed aircraft engines,but the condensation coking problem during engine shutdown is a bottleneck that affects the reusability of aircraft.In this study,a self-designed apparatus was used to separately analyze the condensation coking during the fuel cooling process,and the coking characteristics under different temperature conditions were obtained.The condensation coking mechanism of fuel during cooling process was proposed based on the changes in physical properties of coking precursors obtained by the group contribution method.When the temperature drops to 300℃,not only the gas yield and conversion increase to 71.42% and 89.75% respectively,but the coke mass on the inner surface of the tube also significantly increases from 0.39 to 1.92 mg.Meanwhile,as the temperature further decreases,the morphology of coke gradually transforms into amorphous carbon with a higher degree of graphitization.During the cooling process,due to the liquefaction of coking precursors,their physical properties such as viscosity,density,and saturated vapor pressure undergo sudden changes at 300℃,leading to enhanced intermolecular physical interactions and promoting the physical aggregation of coking precursor molecules,which are deposited on the inner wall of the tube.This work provides a theoretical basis for the subsequent study of condensation coking mechanisms and inhibition methods.
基金the National Natural Science Foundation of China(U1908225,U1702253)the Special Funds for Ba-sic Research Operations of Central Universities(N182515007,N170908001,N2025004).
文摘Compared with Pidgeon process,the relative vacuum continuous magnesium smelting process reduces the ratio of material to magnesium by changing raw materials and the direct reduction after calcination of prefabricated pellets,so that the energy consumption per ton of magnesium produced is reduced by 30∼40%,and the carbon emission is reduced by 43∼52%,breaking through the vacuum conditions to achieve continuous production.However,in the process of industrialization,it was found that the magnesium yield in the condenser was low.Therefore,this paper constructs a condenser model of relative vacuum continuous magnesium refining process,and comprehensively analyzes the condensation mechanism of magnesium vapor through simulation and experiment.It is found that the dynamic characteristics of magnesium vapor condensation is an important index to measure its continuity.Under the condition offlowing argon as the protective gas,when the condensation plate spacing is 10 cm,the surface roughness amplitude variance is 2,and the carrier gasflow rate is 20×10^(-3) m/s,the magnesium vapor has a better condensation effect,and the condensation efficiency formula is derived.
基金supported by the National Natural Science Foundation of China(Nos.51973025 and 52222307)Jilin Science and Technology Bureau(Nos.20220204107YY and 20230204086YY)+1 种基金Changchun Science and Technology Bureau(No.21ZGY06)Jilin Province Development and Reform Commission(No.2023C028-4).
文摘Elastomers are widely used in various fields owing to their excellent tensile properties.Recyclable and self-healing properties are key to extending the service life of elastomers.Accumulating evidence indicates that dynamic covalent chemistry has emerged as a powerful tool for constructing recyclable and self-healing materials.In this work,we demonstrate the preparation of a recyclable and self-healable polydimethylsiloxane(PDMS)elastomer based on the Knoevenagel condensation(KC)reaction.This PDMS elastomer was prepared by the KC reaction catalyzed by 4-dimethylaminopyridine(DMAP).The obtained PDMS elastomer exhibited an elongation at break of 266%,a tensile strength of 0.57 MPa,and a good thermal stability(Td=357℃).In addition,because of the presence of dynamic C=C bonds formed by the KC reaction and low glass transition temperature(Tg=-117℃).This PDMS exhibited good self-healing and recycling properties at room temperature and could be reprocessed by hot pressing.In addition,the PDMS elastomer exhibits good application prospects in the fields of adhesives and flexible electronic devices.
基金supported by National Natural Science Foundation of China(No.21573276)Natural Science Foundation of Jiangsu Province(No.BK20170007)Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB846).
文摘Utilizing superwettability micro/nanostructures to enhance the condensation heat transfer(CHT)performance of engineering materials has attracted great interest due to its values in basic research and technological innovations.Currently,exploring facile micro/nanofabrication approaches to create high-efficiency CHT surfaces has been one of research hotspots.In this work,we propose and demonstrate a type of new superwettability hybrid surface for high-efficiency CHT,which consists of superhydrophobic nanoneedle arrays and triangularly-patterned superhydrophilic microdots(SMDs).Such hybrid surface can be fabricated by the facile growth of densely-packed ZnO nanoneedles on the Zn-electroplated copper surface followed by fluorosilane modification and mask-assisted photodegradation.Through regulating the diameters and interspaces of SMDs,we obtain the optimized triangularly-patterned hybrid surface,which shows 42.7%higher CHT coefficient than the squarely-patterned hybrid surface and 58.5%higher CHT coefficient than the superhydrophobic surface.The key of such hybrid surface design is to considerably increase CHT coefficient brought about by SMD-triggered drop sweeping at the cost of slightly reducing heat transfer area of superhydrophobic functional zone for drop jumping.Such new strategy helps develop advanced CHT surfaces for high-efficiency electronic cooling and energy utilization.
基金supported by the National Natural Science Foundation of China(21476058,U21A20306,21506046 and 21978066)。
文摘The self-condensation of n-butanal is an important reaction for carbon-chain extension in the commercial production of 2-ethylhexanol.Moreover,aldol condensation is one of the important reactions for the synthesis of valuable organic chemicals or transportation fuels from biomass-derived platform compounds.So the investigation of the self-condensation of n-butanal is of significance in both academia and industry.This contribution reviewed the catalytic performance of heterogeneous catalysts in the self-condensation of n-butanal and the related reaction mechanism,network,and kinetics.The purpose of this review is to dedicate some help for further development of environmentally friendly catalysts and for a thorough comprehension of aldol condensation.
基金financially supported by the Norwegian Ferroalloy Producers Research Association (FFF) and the Research Council of Norway through KSP project 326581 Recursive。
文摘The production processes for Si and FeSi have traditionally been considered slag-free.However,recent excavations have revealed significant accumulation of CaO–SiO_(2)–Al_(2)O_(3)slag within the furnaces.This accumulation can obstruct the flow of materials and gases,resulting in lower metal yield and higher energy consumption.The main objective of the current work is to enhance our understanding of slag formation during Si and FeSi production.We investigate slag formation through the dissolution of limestone and iron oxide in quartz and condensate,focusing on the reactions between these materials at a gram scale.Our findings indicate that most slag reaches equilibrium relatively quickly at temperatures starting from 1673 K.Notably,slag formation starts at lower temperature when the iron source is present (1573 K) compared to when only CaO is involved (1673 K).The minor elements tend to accumulate at quartz grain boundaries prior to slag formation.Furthermore,the slag produced from condensate contains less SiO_(2)than that generated from quartz with limestone.The type of quartz source and SiO_(2)phase appears to have little influence on slag formation.Good wettability is a significant factor in reaction between quartz and slag.FactSage calculations indicates that the viscosity of the slag ranges from 0.02 to 14.4 Pa·s under furnace conditions,comparable to the viscosity of honey or motor oil at room temperature.
基金support from theNational Natural Science Foundation(Grant No.12204111)the National Key Research and Development Program ofChina(Grant No.2023YFA1407100)Shanghai Pilot Pro-gram for Basic Research(Grant No.22JC1403202)。
文摘Microcavity exciton-polaritons,formed by strong light-matter coupling,are essential for realizing Bose-Einstein condensation and low-threshold lasing.Such polaritonic lasing and condensation have been demonstrated in Ⅲ-Ⅴ semiconductors at liquid helium temperatures.However,the complex fabrication of these microcavities and operating temperatures limit their room-temperature practical application.Here,we experimentally realize room-temperature exciton-polariton condensation and polaritonic lasing in a CsPbBr_(3)perovskite planar microcavity fabricated by the pressing process.Angleresolved photoluminescence spectra demonstrate the strong light-matter coupling and the formation of exciton-polaritons in such a pressed microcavity.Above the critical threshold,mass polaritons accumulating at the bottom of dispersion lead to a narrow emission linewidth and pronounced blueshift,further reinforcing the Bose-Einstein condensation and polaritonic lasing in this system.Our results offer a feasible and effective approach to investigate exciton-polariton condensation and polariton lasing at room temperature.
基金supported by the National Natural Science Foundation of China(No.42077299)the Innovation Program of Chinese Academy of Agricultural Sciences(No.Y2024QC29).
文摘Formamide condensation with Ni can generate the N–C structure,widely recognized as an efficient catalyst for electrocatalytic CO_(2) reduction reaction(CO_(2)RR).To improve the utilization efficiency of Ni atoms,we introduced metal oxides as substrates to modulate the growth of a formamide-Ni(FA-Ni)condensate.FA-Ni@TiO_(2) demonstrated 2.8 times higher partial CO current density and Ni turnover frequency than FA-Ni,which were also higher than those of other FA-Ni@metal oxides,including ZrO_(2),Al_(2)O_(3),Fe_(2)O_(3),and ZnO.The improved performance of CO_(2)RR can be attributed to the Ni content exposed on FA-Ni@TiO_(2) being twice that of the raw FA-Ni condensate.The Fourier transform infrared results suggested that formamide was adsorbed on TiO_(2) via the-CHO group,exposing-NH_(2) for potential interaction with Ni.As a result,Ni atoms were predispersed on the TiO_(2) surface.By contrast,the dispersion of Ni atoms was not enhanced by other metal oxides,such as Al_(2)O_(3),Fe_(2)O_(3),and ZnO,owing to the robust acidity of their surface sites.These metal oxides adsorbed formamide via-NH_(2),leading to the absence of extra-NH_(2) available for binding to Ni atoms.This study provides new insights into the development of appropriate substrates for single-atom catalysts.
基金supported by the National Natural Science Foundation of China(grant number 52404044).
文摘There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct constant volume depletion experiments and investigate the microscopic mechanisms of condensate gas recovery.The aim of the experiments was to reveal the phase-behavior differences between bulk-phase gas and gas contained in porous media.The results revealed that condensate oil recovery in microfluidics experiments was higher than that in PVT cell tests,and nonuniform condensation and evaporation were exclusively observed in the microfluidics experiments.Furthermore,lower pore connectivity resulted in higher depletion recovery,while more developed fractures led to reduced recovery.Specifically,the chip with fewer fractures achieved the highest recovery(71.15%),whereas the highly fractured chip exhibited the lowest recovery(56.11%).These findings demonstrate that oil saturation during the process of constant volume depletion(CVD)of gas condensate within porous media is lower than that observed in the PVT cell,thus providing experimental evidence for optimizing condensate gas development in field applications.
基金supported by the Jingneng Shiyan Thermal Power Co.,Ltd.(TPRI/TR-CA-006-2023)Huaihe Energy Power Group Co.,Ltd.(TPRI/TR-CA-040-2023)Xi'an Thermal Power Research Institute Co.,Ltd.(TPRI/TR-CA-110-2021A/H1).
文摘Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder and expert knowledge to achieve the early warning and causal analysis of condensate water quality abnormalities.An early warning model using an autoencoder model is built based on the historical data affecting the condensate water quality.Next,an analytical model of condensate water quality abnormalities was then developed by combining expert knowledge and trend test algorithms.Two different datasets were used to test the proposed model,respectively.The accuracy of the autoencoder model in the short-period test set is 88.83%,which shows that the early warning model can accurately analyze the condensate water quality data and achieve the purpose of early warning.For the long-time period test set,the model can correctly identify each abnormality and simultaneously indicates the cause of the abnormal condensate water quality.The proposed model can correctly identify abnormal working conditions and it is applicable to other thermal power plants.
基金Projects supported by the Natural Science Foundation of Hunan Province(2016JJ6020)the Scientific Research Fund of Hunan Provincial Education Department(18A436)the Scientific Research Fund of Hunan First normal University(XYS13N16)。
文摘We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated atom-atom interaction is equivalent to being constrained by a nonlinear optical lattice.Theoretical analyses show the existence of a steady atomic current in the BEC with a spatially varying phase.Under perturbative conditions,the Melnikov chaos criteria of BECs with a spatially varying phase and a constant one are theoretically obtained,respectively.When the perturbative conditions cannot be satisfied,for a repulsive BEC with a spatially varying phase,numerical simulations demonstrate that changing the initial condition can eliminate the chaotic spatial structure and then the system transitions into a biperiodic spatial structure.Increasing the chemical potential can result in a transition from the biperiodic spatial structure to a single-periodic spatial structure.For an attractive BEC with a spatially varying phase,numerical simulations show that decreasing the chemical potential can lead to a high atomic density,but when the wave number of the laser inducing the optical Feshbach resonance exceeds a critical value,the atomic density falls back to a finite range.Regardless of whether the BEC has a spatially varying phase or a constant one,modulating the laser wave number can effectively suppress the chaotic spatial structure in the BEC and then force it into a regular spatial structure.
