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
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
An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduc...An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduced wave equation.The theoretical solutions for the heave radiating potential to the assigned physical model in the corresponding zones are attained by using the separation of variables approach along with the Fourier expansion.Applying the matching eigenfunction expansion technique and orthogonal conditions,the unknown coefficients that are involved in the radiated potentials are determined.The attained radiation potential allows the computation of hydrodynamic coefficients of the heaving buoy,Power Take-Off damping,and wave quantities.The accuracy of the analytical solution for the hydrodynamic coefficients is demonstrated for different oblique angles with varying numbers of terms in the series solution.The current analytical analysis findings are confirmed by existing published numerical boundary element method simulations.Several numerical results of the hydrodynamic coefficients,power capture,power take-off optimal damping,and transmission coefficients for numerous structural and physical aspects are conducted.It has been noted that the ideal power take-off damping increases as the angle of incidence rises,and the analysis suggests that the ability to capture waves is more effective in shallower waters compared to deeper ones.展开更多
The prevailing narrative instructs us that humane treatment of captured enemy fighters is down to white knights from the western parts of the European continent with their codes of chivalry, or alternatively, the Swis...The prevailing narrative instructs us that humane treatment of captured enemy fighters is down to white knights from the western parts of the European continent with their codes of chivalry, or alternatively, the Swiss businessman Henri Dunant. This contribution challenges that narrative for overlooking, or being ignorant of, the way that societies around the world have approached the matter of the captured enemy fighter. Traces of some of the critical principles about humane treatment that we see in our present law can actually be found in much older societies from outside of Europe. A more accurate and representative way of understanding humanitarianism in the treatment of captured enemy fighters can and must be crafted, with the prevailing Euro-centric account balanced with practices, cultures and faiths from elsewhere. The quest to achieve more humane treatment in armed conflict is first and foremost a battle of the intellect. Narratives and conceptualisations that are more inclusive, recognising and appreciating of the ways of the rest of the world are likely to be more effective in communicating humanitarian ideals. This work adopts a new method of approaching the richness and diversity of the treatment of captured enemy fighters over time and space. This new framework of analysis uses six cross-cutting themes to facilitate a broader international and comparative perspective, and develop a more sophisticated level of understanding. The first theme is how older and indigenous societies approached the matter of captured enemy fighters. The second focuses on religions of the world, and what they teach or require. The third section examines the matter of martial practices and codes of ethics for combatants in certain societies. The fourth category engages with colonisation and decolonisation, and regulation （or non-regulation） of the treatment of captives of war. Fifth is the issue of modernisation and the impact it has had on armed forces and fighters, including on the treatment of captives. The final issue is the shift towards formalised agreements, beginning with the first bilateral agreements and then the multilateral codification exercise that began in the mid-19th century and continues to this day. This framework for analysis leads into a final chapter, presenting a fresh and holistic view on the evolution of prisoner of war protections in the international order. It provides a different way of looking at International Humanitarian Law, starting with this effort at a global understanding of the treatment of captured enemy fighters.展开更多
We demonstrated an efficient solar photovoltaic-powered electrochemical CO_(2) reduction device with a high-pressure CO_(2)-captured liquid feed.In an“air-to-barrel”picture,this device holds promise to avoid both hi...We demonstrated an efficient solar photovoltaic-powered electrochemical CO_(2) reduction device with a high-pressure CO_(2)-captured liquid feed.In an“air-to-barrel”picture,this device holds promise to avoid both high-temperature gaseous CO_(2) regeneration and high energy-cost gas product separation steps,while these steps are necessary for devices with a gaseous CO_(2) feed.To date,solar fuel production with a CO_(2)-saturated liquid feed suffers from high over-potential to suppress the hydrogen evolution reaction and consequently,low solar-to-chemical(STC)energy conversion efficiency.Here,we presented a distinct high-pressure operando strategy,i.e.,we took extra advantage of the high pressure in catalyst synthesis besides in the period of the CO_(2) reduction reaction(CO_(2)RR).The power of this strategy was demonstrated by a proof-of-concept device in which a representative copper catalyst was first synthesized in operando in a high-pressure(50 bar)CO_(2)-saturated KHCO3 solution,and then this high-pressure CO_(2)-captured liquid was converted to solar fuel using the operando synthesized Cu catalyst.This Cu catalyst achieved 95%CO_(2)RR selectivity at the recorded low potential of−0.3 V vs.RHE enabled by the combination of operando facet engineering and oxide derivation.Furthermore,this device achieved a record-high STC efficiency of 21.6%under outdoor illumination,superior to other CO_(2)-saturated liquid-fed devices,and compared favorably to gaseous CO_(2)-fed devices.展开更多
There's a particular draw to Shanghai that other cities in China may never be able to replicate.For many of us who've lived in the ‘city on the sea,’the lure is the nightlife-where debauchery runs rampant in...There's a particular draw to Shanghai that other cities in China may never be able to replicate.For many of us who've lived in the ‘city on the sea,’the lure is the nightlife-where debauchery runs rampant in a place with captivating history.展开更多
There's a particular draw to Shanghai that other cities in China may never be able to replicate・For many of us who've lived in the zcity on the sea/the lure is the nightlife-where debauchery runs rampant in a ...There's a particular draw to Shanghai that other cities in China may never be able to replicate・For many of us who've lived in the zcity on the sea/the lure is the nightlife-where debauchery runs rampant in a place with captivating history.Julian ChoLambert,who also goes by his stage name Lynton(隶霆),moved to Shanghai in 2005.While studying Mandarin at Shanghai International Studies University,he fell in love with the city and has returned just about every year since-barring a global pandemic.展开更多
Zircon crystals,which form directly from igneous melts,are invaluable for probing the deep crustal basement and provide crucial insights into its composition and evolution.Supercontinent cycles,including the formation...Zircon crystals,which form directly from igneous melts,are invaluable for probing the deep crustal basement and provide crucial insights into its composition and evolution.Supercontinent cycles,including the formation and breakup of Columbia,Rodinia,and Gondwana,play a pivotal role in shaping global magmatic and metamorphic records,and deciphering magmatic patterns is critical for unraveling the complex interplay between tectonics and magmatism.This study investigates U-Pb geochronology and trace/rare earth element(REE)compositions of zircons from the Early Cretaceous Tethyan Himalaya Igneous Province,revealing critical insights into Precambrian-Paleozoic magmatic and tectonic evolution.Dominant Paleoproterozoic(2498 Ma,1912 Ma)and Neoproterozoic(826-762 Ma)zircon populations confirm the existence of the Precambrian basement.Neoproterozoic magmatism shows decoupling between light and heavy REE(LREE/HREE)and europium anomalies(Eu/Eu^(*)=Eu_(N)/(Sm_(N)×Gd_(N))^(1/2))during the 826-762 Ma and 725-702 Ma intervals,indicating that the Rodinia margin evolved from Andean-style subduction to continental collision.Early Paleozoic magmatism correlates with Pan-African orogenesis and subsequent Proto-Tethyan Ocean subduction beneath the Indian Craton.Neo-Tethyan initiation(ca.273 Ma)is evidenced by 200-300 Ma zircons which exhibit(1)absence of LREE/HREE-Eu/Eu^(*)crustal thickness correlations,and(2)a thermal peak at 273 Ma.展开更多
The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,th...The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,there is a lack of empirical assessments of early opportunities for CCUS implementation in the cement sector.In this study,a comprehensive onshore and offshore source–sink matching optimization assessment framework for CCUS retrofitting in the cement industry,called the SSM-Cement framework,is proposed.The framework comprises four main modules:the cement plant suitability screening module,the storage site assessment module,the source–sink matching optimization model module,and the economic assessment module.By applying this framework to China,919 candidates are initially screened from 1132 existing cement plants.Further,603 CCUS-ready cement plants are identified,and are found to achieve a cumulative emission reduction of 18.5 Gt CO_(2) from 2030 to 2060 by meeting the CCUS feasibility conditions for constructing both onshore and offshore CO_(2) transportation routes.The levelized cost of cement(LCOC)is found to range from 30 to 96(mean 73)USD·(t cement)^(-1),while the levelized carbon avoidance cost(LCAC)ranges from^(-5) to 140(mean 88)USD·(t CO_(2))^(-1).The northeastern and northwestern regions of China are considered priority areas for CCUS implementation,with the LCAC concentrated in the range of 35 to 70 USD·(t CO_(2))^(-1).In addition to onshore storage of 15.8 Gt CO_(2) from 2030 to 2060,offshore storage would contribute 2.7 Gt of decarbonization for coastal cement plants,with comparable LCACs around 90 USD·(t CO_(2))^(-1).展开更多
Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given...Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.展开更多
Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat...Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat transfer,which are widely used in gas adsorption and sep-aration.Metal–organic frameworks(MOFs)with merits like large surface area,inherent porous structure and adjustable topology have been considered as one of the best candidates for PLs construction.This review presents the state-of-the-art status on the fabrication strategy of MOFs-based PLs and their CO_(2) absorption and utilization performance,and the positive effects of porosity and functional modification on the absorption-desorption property,selectivity of target product,and regeneration ability are well summarized.Finally,the challenges and prospects for MOFs-based PLs in the optimization of preparation,the coupling of multiple removal techniques,the in situ characterization methods,the regeneration and cycle stability,the environmental impact as well as expansion of application are proposed.展开更多
Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high po...Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other gases.This review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO_(2)capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit interactions.Besides,the main challenges associated with porous frameworks for CO_(2)capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and emphasized.This review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.展开更多
Carbon capture is an important strategy and is implemented to achieve the goals of CO_(2)reduction and carbon neutrality.As a high energy-efficient technology,membrane-based separation plays a crucial role in CO_(2)ca...Carbon capture is an important strategy and is implemented to achieve the goals of CO_(2)reduction and carbon neutrality.As a high energy-efficient technology,membrane-based separation plays a crucial role in CO_(2)capture.It is urgently needed for membrane-based CO_(2)capture to develop the high-performance membrane materials with high permeability,selectivity,and stability.Herein,ultrapermeable carbon molecular sieve(CMS)membranes are fabricated by py roly zing a finely-engineered benzoxazole-containing copolyimide precursor for efficient CO_(2)capture.The microstructure of CMS membrane has been optimized by initially engineering the precursor-chemistry and subsequently tuning the pyrolysis process.Deep insights into the structure-property relationship of CMSs are provided in detail by a combination of experimental characterization and molecular simulations.We demonstrate that the intrinsically high free volume environment of the precursor,coupled with the steric hindrance of thermostable contorted fragments,promotes the formation of loosely packed and ultramicroporous carbon structures within the resultant CMS membrane,thereby enabling efficient CO_(2)discrimination via size sieving and affinity.The membrane achieves an ultrahigh CO_(2)permeability,good selectivity,and excellent stability.After one month of long-term operation,the CO_(2)permeability in the mixed gas is maintained at 11,800 Barrer,with a CO_(2)/N_(2)selectivity exceeding 60.This study provides insights into the relationship between precursor-chemistry and CMS performance,and our ultrapermeable CMS membrane,which is scalable using thin film manufacturing,holds great potential for industrial CO_(2)capture.展开更多
Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic...Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic sites and their catalytic activity is controversial.In this study,a series of W-based catalysts supported by ZrTiO_(x)were synthesised,and the effects of the intensity,distribution,and type of acid sites were systematically investigated by quantitatively regulating the acidic site properties.The results indicate stronger acidic sites play a more important role in the catalytic reaction.Moreover,the catalysts showed excellent performance only if the Br?nsted acid sites(BASs)and Lewis acid sites(LASs)coexisted.During the catalytic reaction,the BASs facilitated deprotonation,and the LASs promoted the decomposition of carbamates.The ratio of BASs to LASs(B/L)was a critical factor for catalytic activity,wherein optimal performance was achieved when the B/L ratio was close to 1.The 10%HPW/ZrTiO_(x)composite performed better than WO_(3)/ZrTiO_(x)and HSiW/ZrTiO_(x)because it had a stronger acid intensity and a suitable B/L ratio.As a result,the relative heat duty was reduced by 47%compared to 30%aqueous MEA,and the maximum CO_(2)desorption rate was increased by 83%.The Bader charge indicated that the W atoms of HPW/ZrTiO_(x)lost more electrons(0.18)than those of WO_(3)/ZrTiO_(x),which can weaken the O±H bond energy.Consequently,the calculated deprotonation energy is as low as 257 kJ mol^(-1)for HPW/ZrTiO_(x).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Open access funding provided by FCT|FCCN(b-on)the Strategic Research Plan of the Centre for Marine Technology and Ocean Engineering(CENTEC),which is financed by the Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia-FCT)under contract UIDB/UIDP/00134/2020.
文摘An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduced wave equation.The theoretical solutions for the heave radiating potential to the assigned physical model in the corresponding zones are attained by using the separation of variables approach along with the Fourier expansion.Applying the matching eigenfunction expansion technique and orthogonal conditions,the unknown coefficients that are involved in the radiated potentials are determined.The attained radiation potential allows the computation of hydrodynamic coefficients of the heaving buoy,Power Take-Off damping,and wave quantities.The accuracy of the analytical solution for the hydrodynamic coefficients is demonstrated for different oblique angles with varying numbers of terms in the series solution.The current analytical analysis findings are confirmed by existing published numerical boundary element method simulations.Several numerical results of the hydrodynamic coefficients,power capture,power take-off optimal damping,and transmission coefficients for numerous structural and physical aspects are conducted.It has been noted that the ideal power take-off damping increases as the angle of incidence rises,and the analysis suggests that the ability to capture waves is more effective in shallower waters compared to deeper ones.
文摘The prevailing narrative instructs us that humane treatment of captured enemy fighters is down to white knights from the western parts of the European continent with their codes of chivalry, or alternatively, the Swiss businessman Henri Dunant. This contribution challenges that narrative for overlooking, or being ignorant of, the way that societies around the world have approached the matter of the captured enemy fighter. Traces of some of the critical principles about humane treatment that we see in our present law can actually be found in much older societies from outside of Europe. A more accurate and representative way of understanding humanitarianism in the treatment of captured enemy fighters can and must be crafted, with the prevailing Euro-centric account balanced with practices, cultures and faiths from elsewhere. The quest to achieve more humane treatment in armed conflict is first and foremost a battle of the intellect. Narratives and conceptualisations that are more inclusive, recognising and appreciating of the ways of the rest of the world are likely to be more effective in communicating humanitarian ideals. This work adopts a new method of approaching the richness and diversity of the treatment of captured enemy fighters over time and space. This new framework of analysis uses six cross-cutting themes to facilitate a broader international and comparative perspective, and develop a more sophisticated level of understanding. The first theme is how older and indigenous societies approached the matter of captured enemy fighters. The second focuses on religions of the world, and what they teach or require. The third section examines the matter of martial practices and codes of ethics for combatants in certain societies. The fourth category engages with colonisation and decolonisation, and regulation （or non-regulation） of the treatment of captives of war. Fifth is the issue of modernisation and the impact it has had on armed forces and fighters, including on the treatment of captives. The final issue is the shift towards formalised agreements, beginning with the first bilateral agreements and then the multilateral codification exercise that began in the mid-19th century and continues to this day. This framework for analysis leads into a final chapter, presenting a fresh and holistic view on the evolution of prisoner of war protections in the international order. It provides a different way of looking at International Humanitarian Law, starting with this effort at a global understanding of the treatment of captured enemy fighters.
基金supported by the National Natural Science Foundation of China(51888103,52006103,51976090,and 52006101)Scientific and Technological Innovation Project of Carbon Emission Peak and Carbon Neutrality of Jiangsu Province(BE2022024)+1 种基金Natural Science Foundation of Jiangsu Province(BK20200072,BK20200491,and BK20200500)China Postdoctoral Science Foundation(2020M681603)。
文摘We demonstrated an efficient solar photovoltaic-powered electrochemical CO_(2) reduction device with a high-pressure CO_(2)-captured liquid feed.In an“air-to-barrel”picture,this device holds promise to avoid both high-temperature gaseous CO_(2) regeneration and high energy-cost gas product separation steps,while these steps are necessary for devices with a gaseous CO_(2) feed.To date,solar fuel production with a CO_(2)-saturated liquid feed suffers from high over-potential to suppress the hydrogen evolution reaction and consequently,low solar-to-chemical(STC)energy conversion efficiency.Here,we presented a distinct high-pressure operando strategy,i.e.,we took extra advantage of the high pressure in catalyst synthesis besides in the period of the CO_(2) reduction reaction(CO_(2)RR).The power of this strategy was demonstrated by a proof-of-concept device in which a representative copper catalyst was first synthesized in operando in a high-pressure(50 bar)CO_(2)-saturated KHCO3 solution,and then this high-pressure CO_(2)-captured liquid was converted to solar fuel using the operando synthesized Cu catalyst.This Cu catalyst achieved 95%CO_(2)RR selectivity at the recorded low potential of−0.3 V vs.RHE enabled by the combination of operando facet engineering and oxide derivation.Furthermore,this device achieved a record-high STC efficiency of 21.6%under outdoor illumination,superior to other CO_(2)-saturated liquid-fed devices,and compared favorably to gaseous CO_(2)-fed devices.
文摘There's a particular draw to Shanghai that other cities in China may never be able to replicate.For many of us who've lived in the ‘city on the sea,’the lure is the nightlife-where debauchery runs rampant in a place with captivating history.
文摘There's a particular draw to Shanghai that other cities in China may never be able to replicate・For many of us who've lived in the zcity on the sea/the lure is the nightlife-where debauchery runs rampant in a place with captivating history.Julian ChoLambert,who also goes by his stage name Lynton(隶霆),moved to Shanghai in 2005.While studying Mandarin at Shanghai International Studies University,he fell in love with the city and has returned just about every year since-barring a global pandemic.
基金funded by the National Natural Science Foundation of China(42172055)。
文摘Zircon crystals,which form directly from igneous melts,are invaluable for probing the deep crustal basement and provide crucial insights into its composition and evolution.Supercontinent cycles,including the formation and breakup of Columbia,Rodinia,and Gondwana,play a pivotal role in shaping global magmatic and metamorphic records,and deciphering magmatic patterns is critical for unraveling the complex interplay between tectonics and magmatism.This study investigates U-Pb geochronology and trace/rare earth element(REE)compositions of zircons from the Early Cretaceous Tethyan Himalaya Igneous Province,revealing critical insights into Precambrian-Paleozoic magmatic and tectonic evolution.Dominant Paleoproterozoic(2498 Ma,1912 Ma)and Neoproterozoic(826-762 Ma)zircon populations confirm the existence of the Precambrian basement.Neoproterozoic magmatism shows decoupling between light and heavy REE(LREE/HREE)and europium anomalies(Eu/Eu^(*)=Eu_(N)/(Sm_(N)×Gd_(N))^(1/2))during the 826-762 Ma and 725-702 Ma intervals,indicating that the Rodinia margin evolved from Andean-style subduction to continental collision.Early Paleozoic magmatism correlates with Pan-African orogenesis and subsequent Proto-Tethyan Ocean subduction beneath the Indian Craton.Neo-Tethyan initiation(ca.273 Ma)is evidenced by 200-300 Ma zircons which exhibit(1)absence of LREE/HREE-Eu/Eu^(*)crustal thickness correlations,and(2)a thermal peak at 273 Ma.
基金financial support of National Natural Science Foundation of China(72174196 and 71874193)the Open Fund of State Key Laboratory of Coal Resources and Safe Mining(SKLCRSM21KFA05)National Program for Support of Top-Notch Young Professionals.
文摘The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,there is a lack of empirical assessments of early opportunities for CCUS implementation in the cement sector.In this study,a comprehensive onshore and offshore source–sink matching optimization assessment framework for CCUS retrofitting in the cement industry,called the SSM-Cement framework,is proposed.The framework comprises four main modules:the cement plant suitability screening module,the storage site assessment module,the source–sink matching optimization model module,and the economic assessment module.By applying this framework to China,919 candidates are initially screened from 1132 existing cement plants.Further,603 CCUS-ready cement plants are identified,and are found to achieve a cumulative emission reduction of 18.5 Gt CO_(2) from 2030 to 2060 by meeting the CCUS feasibility conditions for constructing both onshore and offshore CO_(2) transportation routes.The levelized cost of cement(LCOC)is found to range from 30 to 96(mean 73)USD·(t cement)^(-1),while the levelized carbon avoidance cost(LCAC)ranges from^(-5) to 140(mean 88)USD·(t CO_(2))^(-1).The northeastern and northwestern regions of China are considered priority areas for CCUS implementation,with the LCAC concentrated in the range of 35 to 70 USD·(t CO_(2))^(-1).In addition to onshore storage of 15.8 Gt CO_(2) from 2030 to 2060,offshore storage would contribute 2.7 Gt of decarbonization for coastal cement plants,with comparable LCACs around 90 USD·(t CO_(2))^(-1).
基金financial support from the National Natural Science Foundation of China(Nos.22278011,22225803,22038001 and 22108007)Beijing Natural Science Foundation(No.Z230023)+1 种基金The Science&Technology Project of Beijing Municipal Education Committee(No.KZ201810005004)Beijing Nova Program(No.Z211100002121094)。
文摘Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.
基金supported by the Natural Science Foundation of China(22106007 and U23A20120)Beijing Natural Science Foundation(8244060)+2 种基金China Postdoctoral Science Foundation(2023M730143)R&D Program of BeijingMunicipal Education Commission(KZ202210005011)Natural Science Foundation of Hebei Province(B2021208033).
文摘Due to the greenhouse effect caused by carbon dioxide(CO_(2))emission,much attention has been paid for the removal of CO_(2).Porous liquids(PLs),as new type of liquid materials,have obvious advantages in mass and heat transfer,which are widely used in gas adsorption and sep-aration.Metal–organic frameworks(MOFs)with merits like large surface area,inherent porous structure and adjustable topology have been considered as one of the best candidates for PLs construction.This review presents the state-of-the-art status on the fabrication strategy of MOFs-based PLs and their CO_(2) absorption and utilization performance,and the positive effects of porosity and functional modification on the absorption-desorption property,selectivity of target product,and regeneration ability are well summarized.Finally,the challenges and prospects for MOFs-based PLs in the optimization of preparation,the coupling of multiple removal techniques,the in situ characterization methods,the regeneration and cycle stability,the environmental impact as well as expansion of application are proposed.
基金the Natural Science Foundation of Shanghai(23ZR1422600)the Innovative research team of high-level local university in Shanghai for their financial support.
文摘Due to the significant impact of carbon dioxide on global ecology,more efforts have been put into the exploration on CO_(2)capture and utilization.Porous organic framework materials,as a kind of materials with high porosity and designable structure,have been considered as effective host materials for adsorbing carbon dioxide or separating it from other gases.This review gives a deep insight into the applications of metal-organic frameworks,covalent-organic frameworks,and other porous frameworks on CO_(2)capture,focusing on the enhanced capture performances originated from their high surface area with abundant porous structure,functional groups with specific heteroatoms modification,or other building unit interactions.Besides,the main challenges associated with porous frameworks for CO_(2)capture and proposed strategies to address these obstacles,including the structural design strategy or the capture mechanism exploration,have been demonstrated and emphasized.This review can contribute to further investigation on porous frameworks for gas capture and separation with enhanced performance and efficiency.
基金financial support from the National Key R&D Program of China(2021YFB3801200)the National Natural Science Foundation of China(22278051,22178044,22308043)CNPC Innovation Found(2022DQ02-0608)。
文摘Carbon capture is an important strategy and is implemented to achieve the goals of CO_(2)reduction and carbon neutrality.As a high energy-efficient technology,membrane-based separation plays a crucial role in CO_(2)capture.It is urgently needed for membrane-based CO_(2)capture to develop the high-performance membrane materials with high permeability,selectivity,and stability.Herein,ultrapermeable carbon molecular sieve(CMS)membranes are fabricated by py roly zing a finely-engineered benzoxazole-containing copolyimide precursor for efficient CO_(2)capture.The microstructure of CMS membrane has been optimized by initially engineering the precursor-chemistry and subsequently tuning the pyrolysis process.Deep insights into the structure-property relationship of CMSs are provided in detail by a combination of experimental characterization and molecular simulations.We demonstrate that the intrinsically high free volume environment of the precursor,coupled with the steric hindrance of thermostable contorted fragments,promotes the formation of loosely packed and ultramicroporous carbon structures within the resultant CMS membrane,thereby enabling efficient CO_(2)discrimination via size sieving and affinity.The membrane achieves an ultrahigh CO_(2)permeability,good selectivity,and excellent stability.After one month of long-term operation,the CO_(2)permeability in the mixed gas is maintained at 11,800 Barrer,with a CO_(2)/N_(2)selectivity exceeding 60.This study provides insights into the relationship between precursor-chemistry and CMS performance,and our ultrapermeable CMS membrane,which is scalable using thin film manufacturing,holds great potential for industrial CO_(2)capture.
基金supported by the National Natural Science Foundation of China(No.52100133,No.52222005)the Key R&D Program of Yunnan Province(No.202303AC100008)。
文摘Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic sites and their catalytic activity is controversial.In this study,a series of W-based catalysts supported by ZrTiO_(x)were synthesised,and the effects of the intensity,distribution,and type of acid sites were systematically investigated by quantitatively regulating the acidic site properties.The results indicate stronger acidic sites play a more important role in the catalytic reaction.Moreover,the catalysts showed excellent performance only if the Br?nsted acid sites(BASs)and Lewis acid sites(LASs)coexisted.During the catalytic reaction,the BASs facilitated deprotonation,and the LASs promoted the decomposition of carbamates.The ratio of BASs to LASs(B/L)was a critical factor for catalytic activity,wherein optimal performance was achieved when the B/L ratio was close to 1.The 10%HPW/ZrTiO_(x)composite performed better than WO_(3)/ZrTiO_(x)and HSiW/ZrTiO_(x)because it had a stronger acid intensity and a suitable B/L ratio.As a result,the relative heat duty was reduced by 47%compared to 30%aqueous MEA,and the maximum CO_(2)desorption rate was increased by 83%.The Bader charge indicated that the W atoms of HPW/ZrTiO_(x)lost more electrons(0.18)than those of WO_(3)/ZrTiO_(x),which can weaken the O±H bond energy.Consequently,the calculated deprotonation energy is as low as 257 kJ mol^(-1)for HPW/ZrTiO_(x).
