The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
tr...The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
traditionally considered to be composed of a Precambrian
metamorphic basement and post-Cambrian cover.
However, the recent geochronological studies show that
the so-called "Precambrian metamorphic rocks^^ are much
younger in age and considered to be formed in the Early
Paleozoic, indicating no existence of the Precambrian
metamorphic basement.展开更多
Multi-element gamma-ray spectrum logging requires standard spectra of individual elements for its interpretation.Since the standard element spectra are usually derived using Monte Carlo simulation of either a pure ele...Multi-element gamma-ray spectrum logging requires standard spectra of individual elements for its interpretation.Since the standard element spectra are usually derived using Monte Carlo simulation of either a pure element or its oxide,we synthesized the standard neutron captured γ spectra（as would be observed using a NaI（Tl） detector） of elements H,Si,Ca and Fe from each element and its oxide.To compare the standard spectra from the elements and oxides,we operated three simulations of sandstone,limestone and mixed formation of sandstone and limestone each with ten different porosities,and used the two kinds of standard spectra to analyze the mixed spectra modeled from sandstone and limestone formations.The results show that the standard element spectra from oxides have more prominent energy peaks than the standard spectra from pure elements.The calculated formation element contents are close to the theoretical values when the standard element spectra from oxides are used to analyze the formation mixed spectra.Therefore,the formation element standard spectra should be calculated from oxide models in the analysis of neutron captured γ spectra by logging tools.展开更多
A novel algorithm of 3-D surface image registration is proposed. It makes use of the array information of 3-D points and takes vector/vertex-like features as the basis of the matching. That array information of 3-D po...A novel algorithm of 3-D surface image registration is proposed. It makes use of the array information of 3-D points and takes vector/vertex-like features as the basis of the matching. That array information of 3-D points can be easily obtained when capturing original 3-D images. The iterative least-mean-squared （LMS） algorithm is applied to optimizing adaptively the transformation matrix parameters. These can effectively improve the registration performance and hurry up the matching process. Experimental results show that it can reach a good subjective impression on aligned 3-D images. Although the algorithm focuses primarily on the human head model, it can also be used for other objects with small modifications.展开更多
Using the single particle theory and the non-flexibility collision model of electron and photon, the influence of the uncaptured electrons on the energy conversion efficiency of multi-photon nonlinear Compton scatteri...Using the single particle theory and the non-flexibility collision model of electron and photon, the influence of the uncaptured electrons on the energy conversion efficiency of multi-photon nonlinear Compton scattering in the extra stationary laser-plasma is investigated. It shows that in extra stationary laser-plasma,the uncaptured electrons make the Δω of the scattering frequency of the multi-photon Compton fall down with the increases of the incident radiation electron speed,the materials of the incident collision of electron and photon, and the number of the photons which work with the electrons at the same time. Under the modulation of the uncaptured electrons to the laser field, the energy conversion efficiency between electrons and photons will fall down with the increase of the electron incident radiation speed, using the low-power electrons for incident source, the loss can be efficiently reduced.展开更多
The global warming issues associated with fossil fuels have forced the world to shift towards environment-friendly alternatives. The studies on the capture and storage of CO<sub>2</sub> have gained signifi...The global warming issues associated with fossil fuels have forced the world to shift towards environment-friendly alternatives. The studies on the capture and storage of CO<sub>2</sub> have gained significant research attention, and to attract the world towards CO<sub>2</sub> capturing and storing, it is necessary to find suitable applications for this captured CO<sub>2</sub>. Methanol is one of the products which can be produced by utilizing the captured CO<sub>2</sub> and hydrogen that can be produced by water splitting. Keeping in view both these green fuel production processes, this study proposes a combined application of both these technologies for the production of methanol, which is an important chemical used in manufacturing industries. This review paper presents a brief study of both carbon capture and hydrogen production technologies. It also provides research trends, economic aspects, and methods of incorporating both these technologies to produce methanol. Additionally, the prospects of the approach in Oman have also been presented.展开更多
Four kinds of Ca-based sorbents were prepared by calcination and hydration reactions using different precursors： calcium hydroxide, calcium carbonate, calcium acetate monohydrate and calcium oxide. The CO2 absorption...Four kinds of Ca-based sorbents were prepared by calcination and hydration reactions using different precursors： calcium hydroxide, calcium carbonate, calcium acetate monohydrate and calcium oxide. The CO2 absorption capacity of those sorbents was investigated in a fixed-bed reactor in the temperature range of 350-650 ℃. It was found that all of those sorbents showed higher capacity for CO2 absorption when the operating temperature higher than 450 ℃. The CaAc2-CaO sorbent showed the highest CO2 absorption capacity of 299 mg.g-1. The mor- phology of those sorbents was examined by scanning electron microscope （SEM）, and the changes of composition before and after carbonation were also determined by X-ray diffraction （XRD）. Results indicated that those sorbents have the similar chemical compositions and crystalline phases before carbonation reaction [mainly Ca（OH）2], and CaCO3 is the main component after carbonation reaction. The SEM morphology shows clearly that the sorbent pores were filled with reaction products after carbonation reaction, and became much denser than before. The N2 adsorption-desorption isotherms indicated that the CaAc2-CaO and CaCO3-CaO sorbents have higher specific surface area. lar2er oore volume and anoropriate pore size distribution than that of CaO-CaO and Ca（OH）2-CaO.展开更多
Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion anal...Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion analysis but has yet to fully explore their utility for capturing faster movements,such as running.Applied studies using markerless systems in clinical and sports settings are still lacking.Thus,the present study compared running biomechanics estimated by marker-based and markerless systems.Given running speed not only affects sports performance but is also associated with clinical injury prevention,diagnosis,and rehabilitation,we aimed to investigate the effects of speed on the comparison of estimated lower extremity joint moments and powers between markerless and marker-based technologies during treadmill running as a concurrent validating study.Methods:Kinematic data from marker-based/markerless technologies were collected,along with ground reaction force data,from 16 young adults running on an instrumented treadmill at 3 speeds:2.24 m/s,2.91 m/s,and 3.58 m/s(5.0 miles/h,6.5 miles/h,and 8.0 miles/h).Sagittal plane moments and powers of the hip,knee,and ankle were calculated by inverse dynamic methods.Time series analysis and statistical parametric mapping were used to determine system differences.Results:Compared to the marker-based system,the markerless system estimated increased lower extremity joint kinetics with faster speed during the swing phase in most cases.Conclusion:Despite the promising application of markerless technology in clinical settings,systematic markerless overestimation requires focused attention.Based on segment pose estimations,the centers of mass estimated by markerless technologies were farther away from the relevant distal joint centers,which led to greater joint moments and powers estimates by markerless vs.marker-based systems.The differences were amplified by running speed.展开更多
An Fe-doped NiO host in a well-defined nanorod assembly (Fe–NiMoO_(4)@NiO-30) with a large surface area is designed to achieve the triple capture of Fe via adjustable surface reconstruction and impregnation to optimi...An Fe-doped NiO host in a well-defined nanorod assembly (Fe–NiMoO_(4)@NiO-30) with a large surface area is designed to achieve the triple capture of Fe via adjustable surface reconstruction and impregnation to optimize the OER activity and durability of bimetallic NiFe hydroxides. The defective and robust NiO layer can not only ensure the first capture of Fe atoms through fast impregnation, but also prevent structural collapse and maintain large Fe adsorption layers. In addition, Fe is found to promote the reconstruction process, leading to more defects to facilitate the second capture. Moreover, the reconfiguration can be controlled by adjusting the ratio of Fe and Ni, obtaining appropriate and uniform dynamically stable Fe sites followed by the third trapping. This triple capture can maintain the dynamic balance of the dissolution and redeposition of active species. Thus, an elevated catalytic performance can be expected with an overpotential of 275 mV at 100 mA cm^(-2) and favorable durability.展开更多
Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical vi...Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical views between cameras are interpolated by depth image-based rendering technique. An improved technique for depth estimation reduces the estimation error and high-density light-field is obtained. The captured data is employed for the calculation of computer hologram using ray-sampling plane. This technique enables high-resolution display even in deep 3D scene although a hologram is calculated from ray information, and thus it makes use of the important advantage of holographic 3D display.展开更多
This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mi...This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mission is disturbed by the measurement noise and the target adversarial behavior.To address these problems,a model-free Combined Adaptive-length Datadriven Predictive Controller(CADPC)is proposed.It consists of a separated subsystem identification method and a combined predictive control strategy.The subsystem identification method is composed of an adaptive data length,thereby reducing sensitivity to undetermined measurement noises and disturbances.Based on the subsystem identification,the combined predictive controller is established,reducing calculating resource.The stability of the CADPC is rigorously proven using the Input-to-State Stable(ISS)theorem and the small-gain theorem.Simulations demonstrate that CADPC effectively handles the model-free space robot post operation in the presence of significant disturbances,state measurement noise,and control input errors.It achieves improved steady-state accuracy,reduced steady-state control consumption,and minimized control input chattering.展开更多
CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development o...CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.展开更多
The capture of atmospheric carbon dioxide by adsorbents is an important strategy to deal with the greenhouse effect.Compared with traditional CO_(2) adsorption materials like activated carbon,silica gel,and zeolite mo...The capture of atmospheric carbon dioxide by adsorbents is an important strategy to deal with the greenhouse effect.Compared with traditional CO_(2) adsorption materials like activated carbon,silica gel,and zeolite molecular sieves,covalent organic frameworks(COFs)have excellent thermal and chemical stabilities and can be produced in many different forms.Using their different possible construction units,ordered structures for specific applications can be produced,giving them broad prospects in fields such as gas storage.This review analyzes the different types of COFs that have been synthesized and their different methods of CO_(2) capture.It then discusses different ways to increase CO_(2) adsorption by changing the internal structure of COFs and modifying their surfaces.The limitations of COF-derived carbon materials in CO_(2) capture are reviewed and,finally,the key role of machine learning and computational simulation in improving CO_(2) adsorption is mentioned,and the current status and future possible uses of COFs are summarized.展开更多
As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2...As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2) emissions while producing value-added chemicals and fuels.However,conventional CCU strategies typically decouple the CO_(2) capture and electrochemical conversion processes,resulting in increased system complexity,higher energy demands,and limited economic viability.Building an integrated system of CO_(2) capture and in-situ electroreduction can bridge the technological gap,reduce costs,and ultimately enhance carbon cycle efficiency.In this review,we highlight recent advances in CO_(2) capture and in-situ electroreduction technologies.We first evaluate the strengths and limitations of conventional CCU technologies and the emerging CO_(2) capture and direct utilization technologies.Subsequently,we summarize the breakthroughs in multifunctional catalyst systems and key catalyst optimization strategies,and analyze the mechanisms behind the performance improvement.Meanwhile,we also discuss the application progress of in-situ techniques and theoretical calculations in CO_(2) capture and in-situ electroreduction.Finally,we outline the unresolved scientific and engineering challenges and propose future research directions to accelerate the development of CO_(2) capture and in-situ electroreduction.展开更多
The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guid...The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.展开更多
A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon cap...A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.展开更多
Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in mariti...Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in maritime shipping using the levelized cost of energy methodology.It includes a detailed comparative analysis based on essential criteria and sensitivity assessments to highlight the economic impacts of technological advancements.Key factors influencing total costs include fuel costs,carbon pricing,and energy demands for carbon capture.The findings reveal that methanol is more cost-effective than heavy fuel oil(HFO)when priced below 3000 CNY/t,assuming HFO costs 4400 CNY/t.Additionally,methanol with post-combustion carbon capture is less expensive than pre-combustion carbon capture.When carbon prices rise above 480 CNY/t,carbon capture technologies prove more economical than purchasing carbon emission allowances for HFO and liquefied natural gas.Enhanc-ing the use of exhaust gas waste heat is recommended for cost savings.Post-combustion carbon capture also shows greater efficiency,requiring about 1.1 GJ/t less energy than pre-combustion methods,leading to lower overall costs.Future research should focus on market mechanisms to stabilize fuel prices and develop less energy-intensive carbon capture technologies.This study offers critical insights into effective decarbonization strategies for advancing global maritime trade in the present and future.展开更多
Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact o...Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact of nitrogen on the properties of materials.The synthesized materials were fully characterized to disclose their textural properties,structural parameters,surface functional groups,elemental compositions,and morphologies.Textural property analysis revealed a remarkable increase in surface areas after alkaline treatment(~1500-2000 m^(2)/g),which was mainly ascribed to the formation of micro-and mesopores.The measurements of structural parameters endorse and complement the findings on textural properties.The asphaltene-derived porous carbons have been employed in energy storage and carbon capture applications.The materials exhibit specific capacitances ranging from 130 to 180 F/g at 0.2 A/g in a 3 M KOH.These results suggest that nitrogen doping significantly enhances the pseudocapacitive behavior of the electroactive materials by promoting Fara-daic redox reactions and improving ion diffusion and adsorption rates.Asphaltene-derived porous carbons also exhibit notable CO_(2)adsorption capacities of 3-4 mmol/g at 25◦C and 1 bar.Also,breakthrough experiments confirm that the N-doped material exhibits remarkable stability,reusability,and increased surface basicity,achieving an impressive CO_(2)uptake of 0.446 mmol/g.These results highlight the potential of asphaltene-based porous carbons as efficient materials for carbon capture and energy storage applications.展开更多
The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely sole...The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.展开更多
Patients affected by monogenic diseases impose a substantial burden on both themselves and their families.The primary preventive measure,i.e.,invasive prenatal diagnosis,carries a risk of miscarriage and cannot be per...Patients affected by monogenic diseases impose a substantial burden on both themselves and their families.The primary preventive measure,i.e.,invasive prenatal diagnosis,carries a risk of miscarriage and cannot be performed early in pregnancy.Hence,there is a need for non-invasive prenatal testing(NIPT)for monogenic diseases.By utilizing enriched cell-free fetal DNA(cffDNA)from maternal plasma,we refine the NIPT method,which combines targeted region capture technology,haplotyping,and analysis of informative site frequency.We apply this method to 93 clinical families at genetic risk for thalassemia,encompassing various genetic variant types,to establish a workflow and evaluate its efficiency.Our approach requires only 3 ng of DNA input to generate 0.1 Gb informative target genomic data and leverages a minimum of 3%cffDNA.This method has a 98.16%success rate and 100%concordance with conventional invasive methods.Furthermore,we demonstrate the ability to analyze fetal genotypes as early as eight weeks of gestation.This study establishes an optimized NIPT method for the early detection of various thalassemia disorders during pregnancy.This technique demonstrates high accuracy and potential for clinical application in prenatal diagnosis.展开更多
Parasitic interface side reactions and uncontrollable Zn deposition seriously erode the cycling performance of aqueous zinc ion batteries,thus impeding the large-scale application.Herein,an organic acid molecule with ...Parasitic interface side reactions and uncontrollable Zn deposition seriously erode the cycling performance of aqueous zinc ion batteries,thus impeding the large-scale application.Herein,an organic acid molecule with a unique molecular structure,camphorsulfonic acid(CSA),is first proposed to remodel the interface microenvironment as an electrolyte additive.The proton provided by CSA can neutralize the hydroxide ions generated by side reactions and inhibit the accumulation of alkaline by-products.The sulfonic acid groups are firmly adsorbed on the Zn anode surface,thereby enabling the regulation of interfacial species.Specifically,oxygen-containing functional groups combined with hydrophobic rigid carbon rings achieve a water-poor interface environment and promote the transfer of Zn^(2+),providing a suitable environment for Zn deposition.As a result,Zn//Zn symmetrical battery can run for over 2800 h(2 mA cm^(-2)-2 mAh cm^(-2)),demonstrating 28-times lifespan compared to the battery without CSA.Furthermore,Zn//KVO full cell presents excellent performance of 800 cycles at 3 A g^(-1).Besides,the pouch cell with CSA can also operate a capacity of 153.8 mAh after 60 cycles at 0.5 A g^(-1) with96.5%capacity retention rate.This work provides an organism-inspired additive selection for stabilizing the interface chemistry of the Zn anode.展开更多
基金supported by the China Geological Survey (grant No. DD20160047-02)the Young Scientists Fund of Shandong Province (grant No. ZR2016DB08)the Financial Fund of Shandong Province (grant No. 2017CXGC1604)
文摘The Xing'an Block (XB) is located between the Erguna
Block (EB) and the Songnen Block (SB), which
topographically occupies the northeastern half of the Great
Xing'an Range (Liu et al., 2017). The XB was
traditionally considered to be composed of a Precambrian
metamorphic basement and post-Cambrian cover.
However, the recent geochronological studies show that
the so-called "Precambrian metamorphic rocks^^ are much
younger in age and considered to be formed in the Early
Paleozoic, indicating no existence of the Precambrian
metamorphic basement.
基金supported by National Natural Science Foundation of China (Grant No. 41074101)Science Foundation of China University of Petroleum(Beijing) (No. KYJJ2012-05-12)
文摘Multi-element gamma-ray spectrum logging requires standard spectra of individual elements for its interpretation.Since the standard element spectra are usually derived using Monte Carlo simulation of either a pure element or its oxide,we synthesized the standard neutron captured γ spectra（as would be observed using a NaI（Tl） detector） of elements H,Si,Ca and Fe from each element and its oxide.To compare the standard spectra from the elements and oxides,we operated three simulations of sandstone,limestone and mixed formation of sandstone and limestone each with ten different porosities,and used the two kinds of standard spectra to analyze the mixed spectra modeled from sandstone and limestone formations.The results show that the standard element spectra from oxides have more prominent energy peaks than the standard spectra from pure elements.The calculated formation element contents are close to the theoretical values when the standard element spectra from oxides are used to analyze the formation mixed spectra.Therefore,the formation element standard spectra should be calculated from oxide models in the analysis of neutron captured γ spectra by logging tools.
文摘A novel algorithm of 3-D surface image registration is proposed. It makes use of the array information of 3-D points and takes vector/vertex-like features as the basis of the matching. That array information of 3-D points can be easily obtained when capturing original 3-D images. The iterative least-mean-squared （LMS） algorithm is applied to optimizing adaptively the transformation matrix parameters. These can effectively improve the registration performance and hurry up the matching process. Experimental results show that it can reach a good subjective impression on aligned 3-D images. Although the algorithm focuses primarily on the human head model, it can also be used for other objects with small modifications.
文摘Using the single particle theory and the non-flexibility collision model of electron and photon, the influence of the uncaptured electrons on the energy conversion efficiency of multi-photon nonlinear Compton scattering in the extra stationary laser-plasma is investigated. It shows that in extra stationary laser-plasma,the uncaptured electrons make the Δω of the scattering frequency of the multi-photon Compton fall down with the increases of the incident radiation electron speed,the materials of the incident collision of electron and photon, and the number of the photons which work with the electrons at the same time. Under the modulation of the uncaptured electrons to the laser field, the energy conversion efficiency between electrons and photons will fall down with the increase of the electron incident radiation speed, using the low-power electrons for incident source, the loss can be efficiently reduced.
文摘The global warming issues associated with fossil fuels have forced the world to shift towards environment-friendly alternatives. The studies on the capture and storage of CO<sub>2</sub> have gained significant research attention, and to attract the world towards CO<sub>2</sub> capturing and storing, it is necessary to find suitable applications for this captured CO<sub>2</sub>. Methanol is one of the products which can be produced by utilizing the captured CO<sub>2</sub> and hydrogen that can be produced by water splitting. Keeping in view both these green fuel production processes, this study proposes a combined application of both these technologies for the production of methanol, which is an important chemical used in manufacturing industries. This review paper presents a brief study of both carbon capture and hydrogen production technologies. It also provides research trends, economic aspects, and methods of incorporating both these technologies to produce methanol. Additionally, the prospects of the approach in Oman have also been presented.
基金Supported by the National Natural Science Foundation of China （21006053）, the Fundamental Research Funds for the Central Universities （65010551） and Special Projects of Environmental Protection （2009ZX07208）.
文摘Four kinds of Ca-based sorbents were prepared by calcination and hydration reactions using different precursors： calcium hydroxide, calcium carbonate, calcium acetate monohydrate and calcium oxide. The CO2 absorption capacity of those sorbents was investigated in a fixed-bed reactor in the temperature range of 350-650 ℃. It was found that all of those sorbents showed higher capacity for CO2 absorption when the operating temperature higher than 450 ℃. The CaAc2-CaO sorbent showed the highest CO2 absorption capacity of 299 mg.g-1. The mor- phology of those sorbents was examined by scanning electron microscope （SEM）, and the changes of composition before and after carbonation were also determined by X-ray diffraction （XRD）. Results indicated that those sorbents have the similar chemical compositions and crystalline phases before carbonation reaction [mainly Ca（OH）2], and CaCO3 is the main component after carbonation reaction. The SEM morphology shows clearly that the sorbent pores were filled with reaction products after carbonation reaction, and became much denser than before. The N2 adsorption-desorption isotherms indicated that the CaAc2-CaO and CaCO3-CaO sorbents have higher specific surface area. lar2er oore volume and anoropriate pore size distribution than that of CaO-CaO and Ca（OH）2-CaO.
文摘Background:The development of computer vision technology has enabled the use of markerless movement tracking for biomechanical analysis.Recent research has reported the feasibility of markerless systems in motion analysis but has yet to fully explore their utility for capturing faster movements,such as running.Applied studies using markerless systems in clinical and sports settings are still lacking.Thus,the present study compared running biomechanics estimated by marker-based and markerless systems.Given running speed not only affects sports performance but is also associated with clinical injury prevention,diagnosis,and rehabilitation,we aimed to investigate the effects of speed on the comparison of estimated lower extremity joint moments and powers between markerless and marker-based technologies during treadmill running as a concurrent validating study.Methods:Kinematic data from marker-based/markerless technologies were collected,along with ground reaction force data,from 16 young adults running on an instrumented treadmill at 3 speeds:2.24 m/s,2.91 m/s,and 3.58 m/s(5.0 miles/h,6.5 miles/h,and 8.0 miles/h).Sagittal plane moments and powers of the hip,knee,and ankle were calculated by inverse dynamic methods.Time series analysis and statistical parametric mapping were used to determine system differences.Results:Compared to the marker-based system,the markerless system estimated increased lower extremity joint kinetics with faster speed during the swing phase in most cases.Conclusion:Despite the promising application of markerless technology in clinical settings,systematic markerless overestimation requires focused attention.Based on segment pose estimations,the centers of mass estimated by markerless technologies were farther away from the relevant distal joint centers,which led to greater joint moments and powers estimates by markerless vs.marker-based systems.The differences were amplified by running speed.
基金supported by the National Natural Science Foundation of China(52174283)the Shandong Provincial Natural Science Foundation(ZR2020MB044)the Qingdao Science and Technology Benefiting People Special Project(20-3-4-8-nsh)。
文摘An Fe-doped NiO host in a well-defined nanorod assembly (Fe–NiMoO_(4)@NiO-30) with a large surface area is designed to achieve the triple capture of Fe via adjustable surface reconstruction and impregnation to optimize the OER activity and durability of bimetallic NiFe hydroxides. The defective and robust NiO layer can not only ensure the first capture of Fe atoms through fast impregnation, but also prevent structural collapse and maintain large Fe adsorption layers. In addition, Fe is found to promote the reconstruction process, leading to more defects to facilitate the second capture. Moreover, the reconfiguration can be controlled by adjusting the ratio of Fe and Ni, obtaining appropriate and uniform dynamically stable Fe sites followed by the third trapping. This triple capture can maintain the dynamic balance of the dissolution and redeposition of active species. Thus, an elevated catalytic performance can be expected with an overpotential of 275 mV at 100 mA cm^(-2) and favorable durability.
基金partly supported by the JSPS Grant-in-Aid for Scientific Research #17300032
文摘Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical views between cameras are interpolated by depth image-based rendering technique. An improved technique for depth estimation reduces the estimation error and high-density light-field is obtained. The captured data is employed for the calculation of computer hologram using ray-sampling plane. This technique enables high-resolution display even in deep 3D scene although a hologram is calculated from ray information, and thus it makes use of the important advantage of holographic 3D display.
基金supported by the National Natural Science Foundation of China(No.12372045)the National Key Research and the Development Program of China(Nos.2023YFC2205900,2023YFC2205901)。
文摘This paper solves the problem of model-free dual-arm space robot maneuvering after non-cooperative target capture under high control quality requirements.The explicit system model is unavailable,and the maneuvering mission is disturbed by the measurement noise and the target adversarial behavior.To address these problems,a model-free Combined Adaptive-length Datadriven Predictive Controller(CADPC)is proposed.It consists of a separated subsystem identification method and a combined predictive control strategy.The subsystem identification method is composed of an adaptive data length,thereby reducing sensitivity to undetermined measurement noises and disturbances.Based on the subsystem identification,the combined predictive controller is established,reducing calculating resource.The stability of the CADPC is rigorously proven using the Input-to-State Stable(ISS)theorem and the small-gain theorem.Simulations demonstrate that CADPC effectively handles the model-free space robot post operation in the presence of significant disturbances,state measurement noise,and control input errors.It achieves improved steady-state accuracy,reduced steady-state control consumption,and minimized control input chattering.
基金Supported by National Key R&D Program of China(2025YFE0109700)the National Natural Science Foundation of China(52106150)。
文摘CO_(2) capture and utilization(CCU)technologies have been recognized as crucial strategies for mitigating global warming,reducing carbon emission,and promoting resource circularity.As such,the design and development of related materials have attracted considerable research attention.Carbon-based materials,characterized by tunable pore structures,abundant active sites,high specific surface area,and excellent chemical stability,demonstrate significant potential for applications in CO_(2) capture and utilization.This review systematically analyzes the adsorption behaviors and performance variations of typical carbon materials,including activated carbon,porous carbon,graphene,and carbon nanotubes during CO_(2) capture processes.Concerning CO_(2) utilization,emphasis is placed on recent advances in the catalytic applications of carbon-based materials in key reactions such as methanation,reverse water-gas shift,dry reforming of methane,and alcohol synthesis.Moreover,the benefits and drawbacks of carbon materials in terms of CO_(2) adsorption capacity,catalytic activity,and stability are thoroughly evaluated,and their potential applications in integrated CO_(2) capture and utilization technologies are discussed.Finally,key strategies for enhancing the performance of carbonaceous materials through structural modulation and surface modification are elucidated.This review aims to provide theoretical guidance for the future development and large-scale implementation of carbon-based materials in CCU technologies.
文摘The capture of atmospheric carbon dioxide by adsorbents is an important strategy to deal with the greenhouse effect.Compared with traditional CO_(2) adsorption materials like activated carbon,silica gel,and zeolite molecular sieves,covalent organic frameworks(COFs)have excellent thermal and chemical stabilities and can be produced in many different forms.Using their different possible construction units,ordered structures for specific applications can be produced,giving them broad prospects in fields such as gas storage.This review analyzes the different types of COFs that have been synthesized and their different methods of CO_(2) capture.It then discusses different ways to increase CO_(2) adsorption by changing the internal structure of COFs and modifying their surfaces.The limitations of COF-derived carbon materials in CO_(2) capture are reviewed and,finally,the key role of machine learning and computational simulation in improving CO_(2) adsorption is mentioned,and the current status and future possible uses of COFs are summarized.
基金supported by the National Natural Science Foundations of China(No.52470113 and 52225003,52300125)the 55Engineering Research&Innovation Team Project of Beijing Forestry University(No.BLRC2023B04)Fundamental Research Funds for the Central Universities(QNTD202506)。
文摘As atmospheric CO_(2) concentration continues to rise,carbon capture and utilization(CCU)technology has emerged as a critical strategy toward achieving carbon neutrality.CCU offers a dual advantage of mitigating CO_(2) emissions while producing value-added chemicals and fuels.However,conventional CCU strategies typically decouple the CO_(2) capture and electrochemical conversion processes,resulting in increased system complexity,higher energy demands,and limited economic viability.Building an integrated system of CO_(2) capture and in-situ electroreduction can bridge the technological gap,reduce costs,and ultimately enhance carbon cycle efficiency.In this review,we highlight recent advances in CO_(2) capture and in-situ electroreduction technologies.We first evaluate the strengths and limitations of conventional CCU technologies and the emerging CO_(2) capture and direct utilization technologies.Subsequently,we summarize the breakthroughs in multifunctional catalyst systems and key catalyst optimization strategies,and analyze the mechanisms behind the performance improvement.Meanwhile,we also discuss the application progress of in-situ techniques and theoretical calculations in CO_(2) capture and in-situ electroreduction.Finally,we outline the unresolved scientific and engineering challenges and propose future research directions to accelerate the development of CO_(2) capture and in-situ electroreduction.
基金co-supported by the National Natural Science Foundation of China(Nos.U24B20157,62203031)the Natural Science Foundation of Beijing Municipality,China(No.4242041)+2 种基金the Natural Science Foundation of Zhejiang Province,China(No.LY24F030002)the Aeronautical ScienceFoundation of China(No.2024Z066051001)the Fundamental Research Funds for the Central Universities of China。
文摘The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.
文摘A batch of important national standards for CCUS released.Recently,State Administration for Market Regulation(SAMR)and National Standardization Administration of China(SAC)released 12 national standards for carbon capture,utilization and storage(CCUS),which will come into effect on July 1,2026.
基金supported by the National Key R&D Program of China(No.2022YFC3701500)the Key R&D Plan Projects of Zhejiang Province(No.2024SSYS0072)Zhejiang Provincial Natural Science Foundation(No.LDT23E0601).
文摘Ship operations are crucial to global trade,and their decarbonization is essential to mitigate climate change.This study evaluates the economic viability of existing and emerging decarbonization technologies in maritime shipping using the levelized cost of energy methodology.It includes a detailed comparative analysis based on essential criteria and sensitivity assessments to highlight the economic impacts of technological advancements.Key factors influencing total costs include fuel costs,carbon pricing,and energy demands for carbon capture.The findings reveal that methanol is more cost-effective than heavy fuel oil(HFO)when priced below 3000 CNY/t,assuming HFO costs 4400 CNY/t.Additionally,methanol with post-combustion carbon capture is less expensive than pre-combustion carbon capture.When carbon prices rise above 480 CNY/t,carbon capture technologies prove more economical than purchasing carbon emission allowances for HFO and liquefied natural gas.Enhanc-ing the use of exhaust gas waste heat is recommended for cost savings.Post-combustion carbon capture also shows greater efficiency,requiring about 1.1 GJ/t less energy than pre-combustion methods,leading to lower overall costs.Future research should focus on market mechanisms to stabilize fuel prices and develop less energy-intensive carbon capture technologies.This study offers critical insights into effective decarbonization strategies for advancing global maritime trade in the present and future.
基金financial support provided by Kuwait Institute for Scientific Research(KISR).
文摘Nanoporous carbon materials were synthesized from asphaltenes using a thermo-chemical treatment under an inert atmosphere and in-situ KOH activation.N-doping was also employed in certain samples to reveal the impact of nitrogen on the properties of materials.The synthesized materials were fully characterized to disclose their textural properties,structural parameters,surface functional groups,elemental compositions,and morphologies.Textural property analysis revealed a remarkable increase in surface areas after alkaline treatment(~1500-2000 m^(2)/g),which was mainly ascribed to the formation of micro-and mesopores.The measurements of structural parameters endorse and complement the findings on textural properties.The asphaltene-derived porous carbons have been employed in energy storage and carbon capture applications.The materials exhibit specific capacitances ranging from 130 to 180 F/g at 0.2 A/g in a 3 M KOH.These results suggest that nitrogen doping significantly enhances the pseudocapacitive behavior of the electroactive materials by promoting Fara-daic redox reactions and improving ion diffusion and adsorption rates.Asphaltene-derived porous carbons also exhibit notable CO_(2)adsorption capacities of 3-4 mmol/g at 25◦C and 1 bar.Also,breakthrough experiments confirm that the N-doped material exhibits remarkable stability,reusability,and increased surface basicity,achieving an impressive CO_(2)uptake of 0.446 mmol/g.These results highlight the potential of asphaltene-based porous carbons as efficient materials for carbon capture and energy storage applications.
基金the New Chongqing Innovative Young Talent Project under Grant 2024NSCQ-qncxX0468Dreams Foundation of Jianghuai Advance Technology Center under Grant 2023-ZM01Z007.
文摘The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.
基金supported by the National Key R&D Program of China(2024YFA1802300)the Major Science and Technology Program of Hainan Province(ZDKJ2021037)+4 种基金the Regional Innovation and Development Joint Fund of the National Natural Science Foundation of China(U24A20677)Hainan Province Science and Technology Special Fund(ZDYF2020117,ZDY2024SHFZ143)Hainan Province Science and TechnologyProject(LCXY202102,LCYX202203,LCYX202301,LCYx202502)Innovative research project for postgraduate students in Hainan Medical University(HYYB2021A05)the Hainan Province Clinical Medical Center,and the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202310).
文摘Patients affected by monogenic diseases impose a substantial burden on both themselves and their families.The primary preventive measure,i.e.,invasive prenatal diagnosis,carries a risk of miscarriage and cannot be performed early in pregnancy.Hence,there is a need for non-invasive prenatal testing(NIPT)for monogenic diseases.By utilizing enriched cell-free fetal DNA(cffDNA)from maternal plasma,we refine the NIPT method,which combines targeted region capture technology,haplotyping,and analysis of informative site frequency.We apply this method to 93 clinical families at genetic risk for thalassemia,encompassing various genetic variant types,to establish a workflow and evaluate its efficiency.Our approach requires only 3 ng of DNA input to generate 0.1 Gb informative target genomic data and leverages a minimum of 3%cffDNA.This method has a 98.16%success rate and 100%concordance with conventional invasive methods.Furthermore,we demonstrate the ability to analyze fetal genotypes as early as eight weeks of gestation.This study establishes an optimized NIPT method for the early detection of various thalassemia disorders during pregnancy.This technique demonstrates high accuracy and potential for clinical application in prenatal diagnosis.
基金financially supported by The Excellent Youth Project of the Education Department of Hunan Province(No.24B0008)the National Natural Science Foundation of China(No.52377222)。
文摘Parasitic interface side reactions and uncontrollable Zn deposition seriously erode the cycling performance of aqueous zinc ion batteries,thus impeding the large-scale application.Herein,an organic acid molecule with a unique molecular structure,camphorsulfonic acid(CSA),is first proposed to remodel the interface microenvironment as an electrolyte additive.The proton provided by CSA can neutralize the hydroxide ions generated by side reactions and inhibit the accumulation of alkaline by-products.The sulfonic acid groups are firmly adsorbed on the Zn anode surface,thereby enabling the regulation of interfacial species.Specifically,oxygen-containing functional groups combined with hydrophobic rigid carbon rings achieve a water-poor interface environment and promote the transfer of Zn^(2+),providing a suitable environment for Zn deposition.As a result,Zn//Zn symmetrical battery can run for over 2800 h(2 mA cm^(-2)-2 mAh cm^(-2)),demonstrating 28-times lifespan compared to the battery without CSA.Furthermore,Zn//KVO full cell presents excellent performance of 800 cycles at 3 A g^(-1).Besides,the pouch cell with CSA can also operate a capacity of 153.8 mAh after 60 cycles at 0.5 A g^(-1) with96.5%capacity retention rate.This work provides an organism-inspired additive selection for stabilizing the interface chemistry of the Zn anode.
