Maraging steels have excellent combination of strength and toughness and are extensively used for a variety of aerospace applications. In one such critical application, this steel was used to fabricate shear screws of...Maraging steels have excellent combination of strength and toughness and are extensively used for a variety of aerospace applications. In one such critical application, this steel was used to fabricate shear screws of a stage separation system in a satellite launch vehicle. During assembly preparations, one of the shear screws which connected the separation band and band end block has failed at the first thread. Microstructural analysis revealed that the crack originated from the root of the thread and propagated in an intergranular mode. The failure is attributed to combined effect of stress and corrosion leading to stress corrosion cracking.展开更多
The rapid expansion of supercritical gas technology for high-content CO_(2)separation from natural gas is a promising avenue of research.However,CO_(2)-rich natural gas cools immediately after being separated and expa...The rapid expansion of supercritical gas technology for high-content CO_(2)separation from natural gas is a promising avenue of research.However,CO_(2)-rich natural gas cools immediately after being separated and expands when the CO_(2)dew point is reached in the absence of a refrigerant system.In our previous study,supercritical expansion experiments using various CO_(2)compositions revealed that the JouleeThomson equation gives a significant absolute average error value of 16.28%.This paper describes corrections to the JouleeThomson expansion equation under supercritical conditions with various CO_(2)concentrations.The results show that the trend of the expansion coefficient is highly dependent on the CO_(2)composition.Using an improved JouleeThomson equation of state over a CO_(2)range of 25%e45%mol,the expansion coefficient tends to fall immediately when a rapid expansion occurs.For a supercriticalfluid,the specific heat Cp depends on temperature,pressure,and density changes.The Van der Waals expansion coefficient profile is simulated using MATLAB,resulting in a correction factor of 1.17e1.32 being applied to the Cp value for CO_(2)concentrations of 25%e40%mol,whereby the absolute average error tends to zero.For CO_(2)concen-trations of more than 40%,the JouleeThomson equation cannot be applied because the expansion coefficient exhibits significant errors compared with the experimental data.The expansion coefficient does not directly determine the performance of supercritical expansion,but does affect the vapor fraction.Integrated production systems based on supercritical expansion are expected to produce an annual profit of around US$18 million from turbine expansion and US$489 million from the production of sweet gas with a purity of 96.6%and less than 2%mol CO_(2).展开更多
The riser reactor is the key unit in the fluid catalytic cracking（FCC） process. As the FCC feedstocks become heavier, the product mixture of oil, gas and catalysts must be separated immediately at the outlet of the ...The riser reactor is the key unit in the fluid catalytic cracking（FCC） process. As the FCC feedstocks become heavier, the product mixture of oil, gas and catalysts must be separated immediately at the outlet of the riser to avoid excessive coking. The quick separation system is the core equipment in the FCC unit. China University of Petroleum（Beijing） has developed many kinds of separation system including the fender-stripping cyclone and circulating-stripping cyclone systems, which can increase the separation efficiency and reduce the pressure drop remarkably. For the inner riser system, a vortex quick separation system has been developed. It contains a vortex quick separator and an isolated shell. In order to reduce the separation time, a new type of separator called the short residence time separator system was developed. It can further reduce the separation time to less than 1 s. In this paper, the corresponding design principles,structure and industrial application of these different kinds of separation systems are reviewed. A system that can simultaneously realize quick oil gas separation, quick oil gas extraction and quick pre-stripping of catalysts at the end of the riser is the trend in the future.展开更多
An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced ...An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.展开更多
In this study, the separation and drying efficiency of the excreta, separated into solid and liquid fraction by a flat conveyor belt under a partial slatted floor in a facility for fattening pigs, was determined. Two ...In this study, the separation and drying efficiency of the excreta, separated into solid and liquid fraction by a flat conveyor belt under a partial slatted floor in a facility for fattening pigs, was determined. Two transverse slope angles (4° and 6°) for the flat belts were used, in a trial with pigs from 20.61 to 117.83 kg of live weight (LW), and the sample size was 7 pigs per pen, 42 pigs per room. The flat belt was more efficient with 6° than with 4° slope angle (32.65% vs. 29.91% dry matter content of solid fraction during the whole fattening period, respectively;P ° than for the 4° (1.4137 vs. 1.3030, during the whole fattening period;P °, this efficiency was not improved in finishing period -83.40 to 117.83 kg LW (two extractions per day) with regard to the growth period -20.61 to 83.40 kg LW (one extraction per day). Meanwhile, with 4° it did improved. The ventilation system underneath slat seems to play a key role in the obtained results.展开更多
The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bid...The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bidirectional consistency verification of function and fault paths.This paper proposes an innovative GO-FTA-GERTS dual model that integrates goal-oriented(GO)methods,fault tree analysis(FTA),and graphical evaluation and review technique(GERT)networks.The core innovation lies in constructing a bidirectional logical interlocking mechanism between the GO success tree and the FTA failure tree,leveraging the dynamic state transfer characteristics of GERT to achieve mathematical equivalence verification of function paths and fault paths.Using a specific aircraft ejection subsystem as an example,the model demonstrates excellent accuracy in ultra-low failure probability calculations:the mean system failure probability calculated by the FTA-GERT network is approximately 5.26×10^(−10) per flight hour,meeting airworthiness standards.At the same time,Monte Carlo simulation and Welch’s t-test are also used to verify that the success probability of GO-GERT model is strictly complementary to the system failure probability calculated by FTA-GERT network.This novel model effectively addresses the limitations of static analysis,dynamic path quantification,and rare event evaluation,providing a new method for reliability analysis of critical aviation safety systems.展开更多
Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltr...Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents,offering low energy requirements and minimal carbon footprints.Molecular separation in non-polar solvent system,such as toluene,n-hexane,and n-heptane,has gained paramount importance due to their extensive use in the pharmaceutical,biochemical,and petrochemical industries.In this review,we presented recent advancements in membrane materials,membrane fabrication techniques and their promising applications for separation in nonpolar solvent system,encompassing hydrocarbon separation,bioactive molecule purification and organic solvent recovery.Furthermore,this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.展开更多
Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively sep...Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively separate sphalerite and pyrite under low alkaline conditions.Furthermore,high-quality zinc concentrates with a Zn grade of 58.48%and a recovery of 91.24%through mixed mineral flotation were obtained.The fundamental mechanisms were investigated through surface wettability tests,adsorption capacity tests,LEIS,FTIR,and XPS.The results confirmed that IDS prevents the adsorption of EX on the surface of pyrite,thereby reducing the response and reactivity of pyrite.The introduction of IDS causes the detachment of Cu2+from the Cu-activated pyrite surface.This process allowed IDS to chelate with the Fe sites on the surface of pyrite through the-COO-and N-centered active groups.By contrast,IDS exhibits weaker adhesion on the surface of Cu-activated sphalerite,making it easily displaced by EX through competitive adsorption.展开更多
Phosphorylated sugars,recognized as central intermediates in carbohydrate metabolism and critical precursors for enzymatic synthesis of rare sugars,face significant technical barriers in their industrialscale producti...Phosphorylated sugars,recognized as central intermediates in carbohydrate metabolism and critical precursors for enzymatic synthesis of rare sugars,face significant technical barriers in their industrialscale production.The multi-enzymatic preparation systems for these compounds inherently accumulate complex impurities,including protein-based catalysts,residual substrates,and oligosaccharide byproducts,posing persistent challenges in product separation and biocatalyst recycling.To address this limitation,we conducted a systematic investigation of ultrafiltration-based separation strategies during the multi-enzyme-catalyzed synthesis of fructose-1,6-bisphosphate(FDP),with particular emphasis on membrane fouling mechanisms.By screening the ultrafiltration membranes,UE020 showed the best performance in the model system,achieving significant separation targets:99.97% retention of bovine serum albumin,FDP/maltodextrin separation coefficient of 7.41,and FDP recovery of 93.63%.An analysis of the components of resistance revealed that concentration polarization induced by maltodextrin was the main factor constituting the resistance,irreversible resistance due to bovine serum albumin was a secondary effect,and the resistance constituted by FDP was negligible.A mitigation strategy employing powdered activated carbon for dynamic membrane formation significantly improved system performance,reducing irreversible resistance by 59.14% and enhancing flux recovery by 20.85%.In this study,ultrafiltration was strategically employed to achieve efficient separation of FDP and enzyme recovery.Significantly,we deciphered the synergistic fouling mechanisms arising from interactions within the multicomponent system containing phosphorylated sugars,oligosaccharides,and proteins.These findings provide a mechanistic framework for scaling up multi-enzymatic systems dedicated to phosphorylated sugar biosynthesis,effectively bridging the gap between laboratory-scale synthesis and industrial implementation.展开更多
Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze in...Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.展开更多
Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechani...Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechanisms.This study introduced a novel method that leverages the high binding affinity of vancomycin(Van)and ampicillin sodium(Amp)to vegetative cells,integrated with magnetic separation technology,to selectively collect spores from complex environments by eliminating vegetative cells.First,Van/Amp-modified magnetic Fe_(3)O_(4) nanoparticles(Fe_(3)O_(4) NPs)were synthesized and characterized.Subsequently,these NPs bound vegetative cells,forming magnetic conjugates that could be efficiently removed using a magnetic field.Concurrently,spores were collected with an efficiency exceeding 95%,completing the entire process within 30 min and achieving a spore separation efficiency of up to 10^(5) CFU/mL.This method was successfully applied to actual samples,including tap water and milk.The state of the collected spores was confirmed using Raman spectroscopy and microscopic techniques,verifying that their characteristics matched those of typical spores.The proposed novel method for rapid spore separation,leveraging the"remove bacterial effect'facilitated by Van/Amp-Fe_(3)O_(4) NPs,showed outstanding spore collection capabilities while preserving the excellent physiological state of spores.展开更多
The exosomes hold significant potential in disease diagnosis and therapeutic interventions.The objective of this study was to investigate the potential of aqueous two-phase systems(ATPSs)for the separation of bovine m...The exosomes hold significant potential in disease diagnosis and therapeutic interventions.The objective of this study was to investigate the potential of aqueous two-phase systems(ATPSs)for the separation of bovine milk exosomes.The milk exosome partition behaviors and bovine milk separation were investigated,and the ATPSs and bovine milk whey addition was optimized.The optimal separation conditions were identified as 16%(mass)polyethylene glycol 4000,10%(mass)dipotassium phosphate,and 1%(mass)enzymatic hydrolysis bovine milk whey.During the separation process,bovine milk exosomes were predominantly enriched in the interphase,while protein impurities were primarily found in the bottom phase.The process yielded bovine milk exosomes of 2.0×10^(11)particles per ml whey with high purity(staining rate>90%,7.01×10^(10)particles per mg protein)and high uniformity(polydispersity index<0.03).The isolated exosomes were characterized and identified by transmission electron microscopy,zeta potential and size distribution.The results demonstrated aqueous two-phase extraction possesses a robust capability for the enrichment and separation of exosomes directly from bovine milk whey,presenting a novel approach for the large-scale isolation of exosomes.展开更多
The conventional feedforward hybrid active noise control(FFHANC)system combines the advantages of the feedforward narrowband active noise control(FFNANC)system and the feedforward broadband active noise control(FFBANC...The conventional feedforward hybrid active noise control(FFHANC)system combines the advantages of the feedforward narrowband active noise control(FFNANC)system and the feedforward broadband active noise control(FFBANC)system.To enhance its adaptive adjustment capability under frequency mismatch(FM)conditions,this paper introduces a narrowband frequency adaptive estimation module into the conventional FFHANC system.This module integrates an autoregressive(AR)model and a linear cascaded adaptive notch filter(LCANF),enabling accurate reference signal frequency estimation even under significant FM.Furthermore,in order to improve the coherence between narrowband and broadband components in the system’s error signal and its corresponding control filter for the conventional FFHANC system,this paper proposes an algorithm based on autoregressive bandpass filter bank(AR-BPFB)for error separation.Simulation results demonstrate that the proposed FFHANC system maintains robust performance under high FM conditions and effectively suppresses hybrid-band noise.The AR-BPFB algorithm significantly elevates the convergence speed of the FFHANC system.展开更多
The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molec...The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molecular sieving emerges as the most promising approach,but it will be significantly compromised at high temperatures due to the significant thermal motion.Here,we report a thermally robust zinc-based metal-organic framework(MOF)that can be synthesized on sub-kilogram scale and achieve exceptional C_(3)H_(6)/C_(3)H_(8) separation performances across a broad temperature range(298–353 K).Unlike conventional MOFs suffering from thermal lattice expansion to give poorer selectivity,this new MOF gives the adsorption capacity of C_(3)H_(6)essentially unchanged and that of C_(3)H_(8) negligible at elevated temperatures,outperforming most state-of-the-art adsorbents,in virtue of multiple hydrogen bonds at the aperture.Column breakthrough experiments confirmed the excellent separation capability,and showed no performance degradation over multi-round adsorption-desorption cycles at 353 K.This study addresses the critical challenge of the trade-off between temperature and selectivity in adsorptive separation,which offers new insights into the design of porous structures for highly effective separation at high temperatures.展开更多
This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow con...This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.展开更多
Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials(SPMs)have drawn increased ...Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials(SPMs)have drawn increased attention due to their unique properties and potential applications in self-healing,shape memory,sensors,and flexible electronics.Here,we develop an ionic cluster-optimized microphase separation strategy to enhance the toughening and energy dissipation capabilities of polydisulfide-based supramolecular polymers.The mechanical properties,including Young's modulus and toughness,are significantly improved by integrating the quadruple H-bonding 2-ureido-4-pyrimidone(UPy)induced microphase separation with iron(III)-to-carboxylate ionic clusters.By combining established chemical approaches with adjustable polymer phase ratios,it is revealed that the synergistic effect of these factors expands the interchain spacing,facilitates the formation of microphase domains,and enhances the tolerance of polythioctic acid-based polymers to external mechanical and thermal stimuli,meeting the practical requirements for industrial plastic applications.Moreover,the UPy-functionalized polymers incorporating iron carboxylate clusters exhibit good one-way shape memory behavior with practical applicability at a relatively low recovery temperature.Our work demonstrates a novel strategy for constructing industrially viable shape memory dynamic SPMs and paves the way for future innovations in developing SPMs.展开更多
The removal of trace plutonium(Pu)from uranium products and organic wastes during spent nuclear fuel reprocessing remains a critical challenge,resulting in excessive plutonium content in uranium products and waste org...The removal of trace plutonium(Pu)from uranium products and organic wastes during spent nuclear fuel reprocessing remains a critical challenge,resulting in excessive plutonium content in uranium products and waste organic liquid.Currently,most organic ligands with selective separation functions are lipophilic,while research on water-soluble,highly selective ligands is relatively scarce,and there are also few reports on the single crystal of these ligands coordinating with plutonium.Herein,a hydrophilic multiamide ligand,N,N,N′,N″,N″-hexaethyl-nitrilotriacetamide(NTAamideC2),was synthesized and evaluated for its Pu(Ⅳ)back-extraction efficiency under harsh conditions.Systematic experiments revealed that NTAamideC2 achieved>99%Pu(Ⅳ)back-extraction rate within 15 min across a wide nitric acid concentration range(0-5 M),even with elevated dibutyl phosphate(DBP≤20000 ppm).Remarkably,the separation factor(SFPu/U)reached 767 at 1.5 M HNO_(3),demonstrating exceptional selectivity over uranium(Ⅵ).Spectrophotometric titration and DFT calculations confirmed the formation of 1:1 and 1:2 Pu(Ⅳ)-NTAamideC2 complexes,with log β values of 7.42±0.01 and 13.23±0.02,respectively.Single-crystal X-ray diffraction analysis of{[Pu_(2)(H_(2)O)_(2)(NTAamideC2)_(4)](H_(2)O)_(2)(NO_(3))(ClO_(4))_(7)}revealed a nine-coordinated PuO_(7)N_(2)geometry,where two NTAamideC2 molecules bind via six O and two N atoms.Compared to conventional agents(AHA/HSC),NTAamideC2 exhibited superior acid tolerance and selectivity,aligning with the CHON principle for sustainable nuclear waste management.This work provides a robust strategy for Pu(Ⅳ)removal in uranium purification cycles and advances fundamental insights into Pu coordination chemistry,offering significant potential for industrial nuclear fuel reprocessing.展开更多
Conventional electrolytic methods for separating chemically similar lanthanides(Ln)and actinides(An)are limited by thermodynamics and slow reaction kinetics,restricting their efficiency in rare-earth refining and nucl...Conventional electrolytic methods for separating chemically similar lanthanides(Ln)and actinides(An)are limited by thermodynamics and slow reaction kinetics,restricting their efficiency in rare-earth refining and nuclear fuel recycling.Herein,we report an electroextraction and oxidative back-extraction(EOB)strategy utilizing a LiCl-KCl-KAlCl_(4) molten salt that overcomes these limitations by leveraging divergent interfacial reactivity.The EOB process achieves an exceptional separation factor for Ln/An(>1000),while simultaneously increasing the separation rate by at least one order of magnitude.Through in-situ synchrotron radiation X-ray micro-computed tomography(SR-μCT)and X-ray diffraction(SR-XRD),we capture selective oxidation-induced destabilization of Ln-Al alloys while actinides retain phase stability-directly visualizing the electrochemical alloy transition mechanism.This research redefines the separation of f-block elements in molten salt systems and introduces a multimodal approach to investigating transient interfacial phenomena that are usually inaccessible to conventional metallurgical diagnostics under extreme conditions.展开更多
Biochar has been widely recognized as a promising solid CO_(2)adsorbent with economic and ecological benefits.Industrial CO_(2)emissions originate from diverse sources,while the pore structure and chemical functional ...Biochar has been widely recognized as a promising solid CO_(2)adsorbent with economic and ecological benefits.Industrial CO_(2)emissions originate from diverse sources,while the pore structure and chemical functional groups of biochar exhibit varying degrees of influence on CO_(2)adsorption and separation performance under different adsorption conditions.Therefore,exploring the matching relationship between the physicochemical properties of biochar and its adsorption and separation performance at different adsorption conditions is essential for the development and optimization of carbon-based adsorbents.This study selected the high-performance extreme gradient boosting(XGB)algorithm from various algorithms and utilized it to develop CO_(2),N_(2),CH_(4)adsorption prediction models.Based on this,coupled prediction models were developed for CO_(2)/N_(2)and CO_(2)/CH_(4)adsorption selectivity.Furthermore,feature importance and partial dependence analysis were performed using SHAP values.The results indicate that during CO_(2)adsorption,the influence of the pore structure of biochar outweighs that of its chemical composition.Specifically,the pore structure of 0.4–0.6 nm is the most important property influencing CO_(2)adsorption at low and medium pressure(0–0.6 bar),and the pore structure of 0.6–0.8 nm,as well as the specific surface area contribute the most at high pressure(0.6–1 bar).During CO_(2)selective separation,the CO_(2)/N_(2)mixture is primarily separated through the selective adsorption of CO_(2)by nitrogen functional groups.In contrast,for CO_(2)/CH_(4)mixtures,pore structure<1 nm plays a more critical role in determining adsorption selectivity.In addition,molecular simulation studies further revealed the adsorption filling mechanisms of CO_(2)molecules within different pore sizes and functional groups.Finally,nitrogen-doped biochar was synthesized using de-alkalize lignin as the precursor,KOH as the activating agent,and urea as the nitrogen dopant.CO_(2),N_(2),and CH_(4)isothermal adsorption experiments were conducted,and the experimental results confirmed that the developed prediction models exhibit high accuracy(R^(2)>0.9).展开更多
The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets.Species separation and diamond precipitation have been reported in carbon-hydrogen systems and have bee...The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets.Species separation and diamond precipitation have been reported in carbon-hydrogen systems and have been verified by static and shock compression experiments.Nevertheless,the dynamic formation processes underlying these phenomena remain insufficiently understood.In combination with a deep learning model,we demonstrate that diamonds form through a three-step process involving dissociation,species separation,and nucleation processes.Under shock conditions of 125 GPa and 4590 K,hydrocarbons decompose to give hydrogen and low-molecular-weight alkanes(CH_(4) and C_(2)H_(6)),which escape from the carbon chains,resulting in C/H species separation.The remaining carbon atoms without C-H bonds accumulate and nucleate to form diamond crystals.The process of diamond growth is associated with a critical nucleus size at which the dynamic energy barrier plays a key role.These dynamic processes of diamond formation provide insight into the establishment of a model for the evolution of ice giant planets.展开更多
文摘Maraging steels have excellent combination of strength and toughness and are extensively used for a variety of aerospace applications. In one such critical application, this steel was used to fabricate shear screws of a stage separation system in a satellite launch vehicle. During assembly preparations, one of the shear screws which connected the separation band and band end block has failed at the first thread. Microstructural analysis revealed that the crack originated from the root of the thread and propagated in an intergranular mode. The failure is attributed to combined effect of stress and corrosion leading to stress corrosion cracking.
文摘The rapid expansion of supercritical gas technology for high-content CO_(2)separation from natural gas is a promising avenue of research.However,CO_(2)-rich natural gas cools immediately after being separated and expands when the CO_(2)dew point is reached in the absence of a refrigerant system.In our previous study,supercritical expansion experiments using various CO_(2)compositions revealed that the JouleeThomson equation gives a significant absolute average error value of 16.28%.This paper describes corrections to the JouleeThomson expansion equation under supercritical conditions with various CO_(2)concentrations.The results show that the trend of the expansion coefficient is highly dependent on the CO_(2)composition.Using an improved JouleeThomson equation of state over a CO_(2)range of 25%e45%mol,the expansion coefficient tends to fall immediately when a rapid expansion occurs.For a supercriticalfluid,the specific heat Cp depends on temperature,pressure,and density changes.The Van der Waals expansion coefficient profile is simulated using MATLAB,resulting in a correction factor of 1.17e1.32 being applied to the Cp value for CO_(2)concentrations of 25%e40%mol,whereby the absolute average error tends to zero.For CO_(2)concen-trations of more than 40%,the JouleeThomson equation cannot be applied because the expansion coefficient exhibits significant errors compared with the experimental data.The expansion coefficient does not directly determine the performance of supercritical expansion,but does affect the vapor fraction.Integrated production systems based on supercritical expansion are expected to produce an annual profit of around US$18 million from turbine expansion and US$489 million from the production of sweet gas with a purity of 96.6%and less than 2%mol CO_(2).
文摘The riser reactor is the key unit in the fluid catalytic cracking（FCC） process. As the FCC feedstocks become heavier, the product mixture of oil, gas and catalysts must be separated immediately at the outlet of the riser to avoid excessive coking. The quick separation system is the core equipment in the FCC unit. China University of Petroleum（Beijing） has developed many kinds of separation system including the fender-stripping cyclone and circulating-stripping cyclone systems, which can increase the separation efficiency and reduce the pressure drop remarkably. For the inner riser system, a vortex quick separation system has been developed. It contains a vortex quick separator and an isolated shell. In order to reduce the separation time, a new type of separator called the short residence time separator system was developed. It can further reduce the separation time to less than 1 s. In this paper, the corresponding design principles,structure and industrial application of these different kinds of separation systems are reviewed. A system that can simultaneously realize quick oil gas separation, quick oil gas extraction and quick pre-stripping of catalysts at the end of the riser is the trend in the future.
基金Project (Grant No. DY105-03-01-15) supported by "Tenth FiveYear Plan of R & D of International Deep-Sea" of National OceanMineral Resources R & D Association, China
文摘An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.
文摘In this study, the separation and drying efficiency of the excreta, separated into solid and liquid fraction by a flat conveyor belt under a partial slatted floor in a facility for fattening pigs, was determined. Two transverse slope angles (4° and 6°) for the flat belts were used, in a trial with pigs from 20.61 to 117.83 kg of live weight (LW), and the sample size was 7 pigs per pen, 42 pigs per room. The flat belt was more efficient with 6° than with 4° slope angle (32.65% vs. 29.91% dry matter content of solid fraction during the whole fattening period, respectively;P ° than for the 4° (1.4137 vs. 1.3030, during the whole fattening period;P °, this efficiency was not improved in finishing period -83.40 to 117.83 kg LW (two extractions per day) with regard to the growth period -20.61 to 83.40 kg LW (one extraction per day). Meanwhile, with 4° it did improved. The ventilation system underneath slat seems to play a key role in the obtained results.
基金supported by Shanghai Central Guidance Science and Technology Development Fund(NO:YDZX20233100004008)National Natural Science Foundation of China(NO:T2441003).
文摘The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bidirectional consistency verification of function and fault paths.This paper proposes an innovative GO-FTA-GERTS dual model that integrates goal-oriented(GO)methods,fault tree analysis(FTA),and graphical evaluation and review technique(GERT)networks.The core innovation lies in constructing a bidirectional logical interlocking mechanism between the GO success tree and the FTA failure tree,leveraging the dynamic state transfer characteristics of GERT to achieve mathematical equivalence verification of function paths and fault paths.Using a specific aircraft ejection subsystem as an example,the model demonstrates excellent accuracy in ultra-low failure probability calculations:the mean system failure probability calculated by the FTA-GERT network is approximately 5.26×10^(−10) per flight hour,meeting airworthiness standards.At the same time,Monte Carlo simulation and Welch’s t-test are also used to verify that the success probability of GO-GERT model is strictly complementary to the system failure probability calculated by FTA-GERT network.This novel model effectively addresses the limitations of static analysis,dynamic path quantification,and rare event evaluation,providing a new method for reliability analysis of critical aviation safety systems.
基金supported by the National Natural Science Foundation of China(Grant No.2230081973)Shanghai Pilot Program for Basic Research(22TQ1400100-4).
文摘Membrane technology holds significant potential for augmenting or partially substituting conventional separation techniques,such as heatdriven distillation,thereby reducing energy consumption.Organic solvent nanofiltration represents an advanced membrane separation technology capable of discerning molecules within a molecular weight range of approximately 100-1000 Da in organic solvents,offering low energy requirements and minimal carbon footprints.Molecular separation in non-polar solvent system,such as toluene,n-hexane,and n-heptane,has gained paramount importance due to their extensive use in the pharmaceutical,biochemical,and petrochemical industries.In this review,we presented recent advancements in membrane materials,membrane fabrication techniques and their promising applications for separation in nonpolar solvent system,encompassing hydrocarbon separation,bioactive molecule purification and organic solvent recovery.Furthermore,this review highlighted the challenges and opportunities associated with membrane scale-up strategies and the direct translation of this promising technology into industrial applications.
基金supports from the National Natural Science Foundation of China(No.52174272)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2021zzts0306)the Hunan Provincial Natural Science Foundation of China(No.2020JJ5736).
文摘Tetrasodium iminodisuccinate(IDS)was used as an inhibitor in the separation of sphalerite and pyrite in the EX−Cu(II)(ethyl xanthate and Cu2+)system.The flotation test results demonstrated that IDS can effectively separate sphalerite and pyrite under low alkaline conditions.Furthermore,high-quality zinc concentrates with a Zn grade of 58.48%and a recovery of 91.24%through mixed mineral flotation were obtained.The fundamental mechanisms were investigated through surface wettability tests,adsorption capacity tests,LEIS,FTIR,and XPS.The results confirmed that IDS prevents the adsorption of EX on the surface of pyrite,thereby reducing the response and reactivity of pyrite.The introduction of IDS causes the detachment of Cu2+from the Cu-activated pyrite surface.This process allowed IDS to chelate with the Fe sites on the surface of pyrite through the-COO-and N-centered active groups.By contrast,IDS exhibits weaker adhesion on the surface of Cu-activated sphalerite,making it easily displaced by EX through competitive adsorption.
基金the funding support provided by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDC0120402)the National Key Research&Development Program of China (2022YFC2105103)。
文摘Phosphorylated sugars,recognized as central intermediates in carbohydrate metabolism and critical precursors for enzymatic synthesis of rare sugars,face significant technical barriers in their industrialscale production.The multi-enzymatic preparation systems for these compounds inherently accumulate complex impurities,including protein-based catalysts,residual substrates,and oligosaccharide byproducts,posing persistent challenges in product separation and biocatalyst recycling.To address this limitation,we conducted a systematic investigation of ultrafiltration-based separation strategies during the multi-enzyme-catalyzed synthesis of fructose-1,6-bisphosphate(FDP),with particular emphasis on membrane fouling mechanisms.By screening the ultrafiltration membranes,UE020 showed the best performance in the model system,achieving significant separation targets:99.97% retention of bovine serum albumin,FDP/maltodextrin separation coefficient of 7.41,and FDP recovery of 93.63%.An analysis of the components of resistance revealed that concentration polarization induced by maltodextrin was the main factor constituting the resistance,irreversible resistance due to bovine serum albumin was a secondary effect,and the resistance constituted by FDP was negligible.A mitigation strategy employing powdered activated carbon for dynamic membrane formation significantly improved system performance,reducing irreversible resistance by 59.14% and enhancing flux recovery by 20.85%.In this study,ultrafiltration was strategically employed to achieve efficient separation of FDP and enzyme recovery.Significantly,we deciphered the synergistic fouling mechanisms arising from interactions within the multicomponent system containing phosphorylated sugars,oligosaccharides,and proteins.These findings provide a mechanistic framework for scaling up multi-enzymatic systems dedicated to phosphorylated sugar biosynthesis,effectively bridging the gap between laboratory-scale synthesis and industrial implementation.
基金supported by the National Natural Science Foundation of China(22378285,92475117 and U21A20303)。
文摘Electrochemically switched ion exchange(ESIX)is an effective technology for extracting high-valueadded ions from dilute solutions.This study focuses on Li^(+)extraction by employing a comprehensive model to analyze interaction between fluidic dynamics,electric field and ion transport.The model combines Butler-Volmer equation modified by electroactive site concentration,Nernst-Planck equation and Navier-Stokes equation.It is found that the chamber width affects solution phase resistance,thereby altering the pote ntial distribution and influencing the current distribution within the membrane.A narrow chamber increases current density in the solid phase of the membrane,enhancing Li^(+) extraction.The solution flow-field not only enhances convective transport but also increases the current density in the solid phase,promoting Li^(+) extraction.There is a synergistic effect between fluid-flow-field and electric-field for ion separation,which is only significant when the chamber width is greater than 2 mm.The synergistic mechanism differs from that in the capacitive deionization system.Therefore,the performance decline caused by a wide chamber can be compensated for by increasing the fluid-flow rate,utilizing the synergistic effect between the flu id-flow-field and electric-field to optimize the lithium extraction efficiency in the ESIX system.
基金supported by the General Program of National Natural Science Foundation of China(32472417)the Major Science and Technology Projects in Henan Province(221100110500,231100110400)+2 种基金the Science and Technology Innovation Team of Henan Universities(22IRTSTHN021)the Science and Technology of Henan Province(232102110136)Henan Provincial Joint Fund(Science and Technology Tackling)Category(232103810023).
文摘Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechanisms.This study introduced a novel method that leverages the high binding affinity of vancomycin(Van)and ampicillin sodium(Amp)to vegetative cells,integrated with magnetic separation technology,to selectively collect spores from complex environments by eliminating vegetative cells.First,Van/Amp-modified magnetic Fe_(3)O_(4) nanoparticles(Fe_(3)O_(4) NPs)were synthesized and characterized.Subsequently,these NPs bound vegetative cells,forming magnetic conjugates that could be efficiently removed using a magnetic field.Concurrently,spores were collected with an efficiency exceeding 95%,completing the entire process within 30 min and achieving a spore separation efficiency of up to 10^(5) CFU/mL.This method was successfully applied to actual samples,including tap water and milk.The state of the collected spores was confirmed using Raman spectroscopy and microscopic techniques,verifying that their characteristics matched those of typical spores.The proposed novel method for rapid spore separation,leveraging the"remove bacterial effect'facilitated by Van/Amp-Fe_(3)O_(4) NPs,showed outstanding spore collection capabilities while preserving the excellent physiological state of spores.
基金supported by the National Natural Science Foundation of China(22378350).
文摘The exosomes hold significant potential in disease diagnosis and therapeutic interventions.The objective of this study was to investigate the potential of aqueous two-phase systems(ATPSs)for the separation of bovine milk exosomes.The milk exosome partition behaviors and bovine milk separation were investigated,and the ATPSs and bovine milk whey addition was optimized.The optimal separation conditions were identified as 16%(mass)polyethylene glycol 4000,10%(mass)dipotassium phosphate,and 1%(mass)enzymatic hydrolysis bovine milk whey.During the separation process,bovine milk exosomes were predominantly enriched in the interphase,while protein impurities were primarily found in the bottom phase.The process yielded bovine milk exosomes of 2.0×10^(11)particles per ml whey with high purity(staining rate>90%,7.01×10^(10)particles per mg protein)and high uniformity(polydispersity index<0.03).The isolated exosomes were characterized and identified by transmission electron microscopy,zeta potential and size distribution.The results demonstrated aqueous two-phase extraction possesses a robust capability for the enrichment and separation of exosomes directly from bovine milk whey,presenting a novel approach for the large-scale isolation of exosomes.
基金supported in part by the Postgraduate Research&Practice Innovation Program of Nanjing University of Aeronautics and Astronautics(No.xcxjh20240326).
文摘The conventional feedforward hybrid active noise control(FFHANC)system combines the advantages of the feedforward narrowband active noise control(FFNANC)system and the feedforward broadband active noise control(FFBANC)system.To enhance its adaptive adjustment capability under frequency mismatch(FM)conditions,this paper introduces a narrowband frequency adaptive estimation module into the conventional FFHANC system.This module integrates an autoregressive(AR)model and a linear cascaded adaptive notch filter(LCANF),enabling accurate reference signal frequency estimation even under significant FM.Furthermore,in order to improve the coherence between narrowband and broadband components in the system’s error signal and its corresponding control filter for the conventional FFHANC system,this paper proposes an algorithm based on autoregressive bandpass filter bank(AR-BPFB)for error separation.Simulation results demonstrate that the proposed FFHANC system maintains robust performance under high FM conditions and effectively suppresses hybrid-band noise.The AR-BPFB algorithm significantly elevates the convergence speed of the FFHANC system.
基金supported by the National Natural Science Foundation of China(22475240,22090061,22488101)the State Key Laboratory of Catalysis(2024SKL-A-010)。
文摘The separation of propylene(C_(3)H_(6))and propane(C_(3)H_(8))presents a significant industrial challenge due to their similar molecular dimensions and physicochemical properties.Among various separation methods,molecular sieving emerges as the most promising approach,but it will be significantly compromised at high temperatures due to the significant thermal motion.Here,we report a thermally robust zinc-based metal-organic framework(MOF)that can be synthesized on sub-kilogram scale and achieve exceptional C_(3)H_(6)/C_(3)H_(8) separation performances across a broad temperature range(298–353 K).Unlike conventional MOFs suffering from thermal lattice expansion to give poorer selectivity,this new MOF gives the adsorption capacity of C_(3)H_(6)essentially unchanged and that of C_(3)H_(8) negligible at elevated temperatures,outperforming most state-of-the-art adsorbents,in virtue of multiple hydrogen bonds at the aperture.Column breakthrough experiments confirmed the excellent separation capability,and showed no performance degradation over multi-round adsorption-desorption cycles at 353 K.This study addresses the critical challenge of the trade-off between temperature and selectivity in adsorptive separation,which offers new insights into the design of porous structures for highly effective separation at high temperatures.
基金the Scientific Research Projects Unit of Erciyes University under contract no:FDS-2022-11532 and FOA-2025-14773.
文摘This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.
基金supported by the National Natural Science Foundation of China(No.22375063)Science and Technology Commission of Shanghai Municipality(No.23JC140170O)the Fundamental Research Funds for the Central Universities.
文摘Developing advanced polymeric materials with enhanced mechanical properties and functionalities has been a long-standing goal in materials science.Recently,supramolecular polymeric materials(SPMs)have drawn increased attention due to their unique properties and potential applications in self-healing,shape memory,sensors,and flexible electronics.Here,we develop an ionic cluster-optimized microphase separation strategy to enhance the toughening and energy dissipation capabilities of polydisulfide-based supramolecular polymers.The mechanical properties,including Young's modulus and toughness,are significantly improved by integrating the quadruple H-bonding 2-ureido-4-pyrimidone(UPy)induced microphase separation with iron(III)-to-carboxylate ionic clusters.By combining established chemical approaches with adjustable polymer phase ratios,it is revealed that the synergistic effect of these factors expands the interchain spacing,facilitates the formation of microphase domains,and enhances the tolerance of polythioctic acid-based polymers to external mechanical and thermal stimuli,meeting the practical requirements for industrial plastic applications.Moreover,the UPy-functionalized polymers incorporating iron carboxylate clusters exhibit good one-way shape memory behavior with practical applicability at a relatively low recovery temperature.Our work demonstrates a novel strategy for constructing industrially viable shape memory dynamic SPMs and paves the way for future innovations in developing SPMs.
基金supported by the China Institute of Atomic Energy。
文摘The removal of trace plutonium(Pu)from uranium products and organic wastes during spent nuclear fuel reprocessing remains a critical challenge,resulting in excessive plutonium content in uranium products and waste organic liquid.Currently,most organic ligands with selective separation functions are lipophilic,while research on water-soluble,highly selective ligands is relatively scarce,and there are also few reports on the single crystal of these ligands coordinating with plutonium.Herein,a hydrophilic multiamide ligand,N,N,N′,N″,N″-hexaethyl-nitrilotriacetamide(NTAamideC2),was synthesized and evaluated for its Pu(Ⅳ)back-extraction efficiency under harsh conditions.Systematic experiments revealed that NTAamideC2 achieved>99%Pu(Ⅳ)back-extraction rate within 15 min across a wide nitric acid concentration range(0-5 M),even with elevated dibutyl phosphate(DBP≤20000 ppm).Remarkably,the separation factor(SFPu/U)reached 767 at 1.5 M HNO_(3),demonstrating exceptional selectivity over uranium(Ⅵ).Spectrophotometric titration and DFT calculations confirmed the formation of 1:1 and 1:2 Pu(Ⅳ)-NTAamideC2 complexes,with log β values of 7.42±0.01 and 13.23±0.02,respectively.Single-crystal X-ray diffraction analysis of{[Pu_(2)(H_(2)O)_(2)(NTAamideC2)_(4)](H_(2)O)_(2)(NO_(3))(ClO_(4))_(7)}revealed a nine-coordinated PuO_(7)N_(2)geometry,where two NTAamideC2 molecules bind via six O and two N atoms.Compared to conventional agents(AHA/HSC),NTAamideC2 exhibited superior acid tolerance and selectivity,aligning with the CHON principle for sustainable nuclear waste management.This work provides a robust strategy for Pu(Ⅳ)removal in uranium purification cycles and advances fundamental insights into Pu coordination chemistry,offering significant potential for industrial nuclear fuel reprocessing.
基金supported by the National Science Fund for Distinguished Young Scholars(21925603)the National Natural Science Foundation of China(22306185)the China Postdoctoral Science Foundation(2023M732032)。
文摘Conventional electrolytic methods for separating chemically similar lanthanides(Ln)and actinides(An)are limited by thermodynamics and slow reaction kinetics,restricting their efficiency in rare-earth refining and nuclear fuel recycling.Herein,we report an electroextraction and oxidative back-extraction(EOB)strategy utilizing a LiCl-KCl-KAlCl_(4) molten salt that overcomes these limitations by leveraging divergent interfacial reactivity.The EOB process achieves an exceptional separation factor for Ln/An(>1000),while simultaneously increasing the separation rate by at least one order of magnitude.Through in-situ synchrotron radiation X-ray micro-computed tomography(SR-μCT)and X-ray diffraction(SR-XRD),we capture selective oxidation-induced destabilization of Ln-Al alloys while actinides retain phase stability-directly visualizing the electrochemical alloy transition mechanism.This research redefines the separation of f-block elements in molten salt systems and introduces a multimodal approach to investigating transient interfacial phenomena that are usually inaccessible to conventional metallurgical diagnostics under extreme conditions.
基金supported by the Fundamental Research Funds for the Central Universities(No.2025JC008)the National Natural Science Foundation of China(grant number 52176105)+2 种基金the Science and Technology Project of Hebei Education Department-China(BJK2022063)the Hebei Natural Science Foundation-China(grant number E2025502038)the Funding Program for Cultivating Innovative Abilities of Graduate Students in Hebei Province of China(CXZZBS2025184).
文摘Biochar has been widely recognized as a promising solid CO_(2)adsorbent with economic and ecological benefits.Industrial CO_(2)emissions originate from diverse sources,while the pore structure and chemical functional groups of biochar exhibit varying degrees of influence on CO_(2)adsorption and separation performance under different adsorption conditions.Therefore,exploring the matching relationship between the physicochemical properties of biochar and its adsorption and separation performance at different adsorption conditions is essential for the development and optimization of carbon-based adsorbents.This study selected the high-performance extreme gradient boosting(XGB)algorithm from various algorithms and utilized it to develop CO_(2),N_(2),CH_(4)adsorption prediction models.Based on this,coupled prediction models were developed for CO_(2)/N_(2)and CO_(2)/CH_(4)adsorption selectivity.Furthermore,feature importance and partial dependence analysis were performed using SHAP values.The results indicate that during CO_(2)adsorption,the influence of the pore structure of biochar outweighs that of its chemical composition.Specifically,the pore structure of 0.4–0.6 nm is the most important property influencing CO_(2)adsorption at low and medium pressure(0–0.6 bar),and the pore structure of 0.6–0.8 nm,as well as the specific surface area contribute the most at high pressure(0.6–1 bar).During CO_(2)selective separation,the CO_(2)/N_(2)mixture is primarily separated through the selective adsorption of CO_(2)by nitrogen functional groups.In contrast,for CO_(2)/CH_(4)mixtures,pore structure<1 nm plays a more critical role in determining adsorption selectivity.In addition,molecular simulation studies further revealed the adsorption filling mechanisms of CO_(2)molecules within different pore sizes and functional groups.Finally,nitrogen-doped biochar was synthesized using de-alkalize lignin as the precursor,KOH as the activating agent,and urea as the nitrogen dopant.CO_(2),N_(2),and CH_(4)isothermal adsorption experiments were conducted,and the experimental results confirmed that the developed prediction models exhibit high accuracy(R^(2)>0.9).
基金supported by the National Natural Science Foundation of China(Grant Nos.12534013,12047561,and 12104507)the Science and Technology Innovation Program of Hunan Province(Grant Nos.2025ZYJ001 and 2021RC4026)the National University of Defense Technology Research Fund Project.
文摘The accumulation and circulation of carbon and hydrogen contribute to the chemical evolution of ice giant planets.Species separation and diamond precipitation have been reported in carbon-hydrogen systems and have been verified by static and shock compression experiments.Nevertheless,the dynamic formation processes underlying these phenomena remain insufficiently understood.In combination with a deep learning model,we demonstrate that diamonds form through a three-step process involving dissociation,species separation,and nucleation processes.Under shock conditions of 125 GPa and 4590 K,hydrocarbons decompose to give hydrogen and low-molecular-weight alkanes(CH_(4) and C_(2)H_(6)),which escape from the carbon chains,resulting in C/H species separation.The remaining carbon atoms without C-H bonds accumulate and nucleate to form diamond crystals.The process of diamond growth is associated with a critical nucleus size at which the dynamic energy barrier plays a key role.These dynamic processes of diamond formation provide insight into the establishment of a model for the evolution of ice giant planets.
