Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical char...Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.展开更多
Optical bound states in the continuum(BICs)have recently stimulated a research boom,accompanied by demonstrations of abundant exotic phenomena and applications.With ultrahigh quality(Q)factors,optical BICs have powerf...Optical bound states in the continuum(BICs)have recently stimulated a research boom,accompanied by demonstrations of abundant exotic phenomena and applications.With ultrahigh quality(Q)factors,optical BICs have powerful abilities to trap light in optical structures from the continuum of propagation waves in free space.Besides the high Q factors enabled by the confined properties,many hidden topological characteristics were discovered in optical BICs.Especially in periodic structures with well-defined wave vectors,optical BICs were discovered to carry topological charges in momentum space,underlying many unique physical properties.Both high Q factors and topological vortex configurations in momentum space enabled by BICs bring new degrees of freedom to modulate light.BICs have enabled many novel discoveries in light-matter interactions and spin-orbit interactions of light,and BIC applications in lasing and sensing have also been well explored with many advantages.In this paper,we review recent developments of optical BICs in periodic structures,including the physical mechanisms of BICs,explored effects enabled by BICs,and applications of BICs.In the outlook part,we provide a perspective on future developments for BICs.展开更多
In recent years, nonclassical effects of light field havealways been a very conspicuous subject. In this field an effective approach is to construct as many as possible the nonclassical states of light field that are ...In recent years, nonclassical effects of light field havealways been a very conspicuous subject. In this field an effective approach is to construct as many as possible the nonclassical states of light field that are allowed in the frame of quantum mechanics and then to study their properties, so as to find out the relations of different nonclassical effects or states of light field and to discover new nonclassical effects or states of light field.展开更多
We use quantum field entropy to measure the degree of entanglement for a coherent state light field interacting with two atoms that are initially in an arbitrary two-qubit state. The influence of different mean photon...We use quantum field entropy to measure the degree of entanglement for a coherent state light field interacting with two atoms that are initially in an arbitrary two-qubit state. The influence of different mean photon number of the coherent field on the entropy of the field is discussed in detail when the two atoms are initially in one superposition state of the Bell states. The results show that the mean photon number of the light field can regulate the quantum entanglement between the atoms and light field.展开更多
Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among the...Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among these,tuning spin polarization and introducing an external magnetic field are considered two promising strategies to boost photocatalytic performance.Herein this review highlights the recent breakthroughs through manipulating spin states and applying external magnetic fields for enhancing photocatalytic reactions.The relevant characterization techniques and fundamental mechanisms are summarized.Spin polarization states of photocatalysts have received considerable attention due to their unique roles,including inhibiting the recombination of photoexcited carriers owing to spin orientation constraint,enhancing the reaction product selectivity,and reducing the reaction barriers via optimizing the absorption energy and binding strength.As for the effects of external magnetic field on photocatalytic performance,we mainly discuss the separation enhancement of photoinduced carriers under static and time-varying magnetic fields and the magneto-hydrodynamic effect of charged particles.Lastly,the negative magnetoresistance effect is discussed due to the synergistic effects of the electron spin state and an external magnetic field.These discussions in this review may provide new insights into designing new semiconductors for boosting photocatalytic performance in internal and external magnetic fields.展开更多
基金Supported by the National Natural Science Foundation of China(42172149,U2244209)Sinopec Science and Technology Research Project(P23230,P22132)。
文摘Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.
基金supported by the National Natural Science Foundation of China(Nos.12234007,12221004,12321161645,62325501,62135001,12074049,and 12147102)the National Key R and D Program of China(Nos.2022YFA1404804,2021YFA1400603,and 2023YFA1406900)+4 种基金the Major Program of National Natural Science Foundation of China(Nos.T2394480 and T2394481)the Science and Technology Commission of Shanghai Municipality(Nos.22142200400,21DZ1101500,2019SHZDZX01,and 23DZ2260100)the Fundamental Research Funds for the Central Universities(No.2022CDJQY-007)supported by the China National Postdoctoral Program for Innovative Talents(No.BX20230079)the China Postdoctoral Science Foundation(No.2023M740721).
文摘Optical bound states in the continuum(BICs)have recently stimulated a research boom,accompanied by demonstrations of abundant exotic phenomena and applications.With ultrahigh quality(Q)factors,optical BICs have powerful abilities to trap light in optical structures from the continuum of propagation waves in free space.Besides the high Q factors enabled by the confined properties,many hidden topological characteristics were discovered in optical BICs.Especially in periodic structures with well-defined wave vectors,optical BICs were discovered to carry topological charges in momentum space,underlying many unique physical properties.Both high Q factors and topological vortex configurations in momentum space enabled by BICs bring new degrees of freedom to modulate light.BICs have enabled many novel discoveries in light-matter interactions and spin-orbit interactions of light,and BIC applications in lasing and sensing have also been well explored with many advantages.In this paper,we review recent developments of optical BICs in periodic structures,including the physical mechanisms of BICs,explored effects enabled by BICs,and applications of BICs.In the outlook part,we provide a perspective on future developments for BICs.
基金Project partly supported by the National Natural Science Foundation of China.
文摘In recent years, nonclassical effects of light field havealways been a very conspicuous subject. In this field an effective approach is to construct as many as possible the nonclassical states of light field that are allowed in the frame of quantum mechanics and then to study their properties, so as to find out the relations of different nonclassical effects or states of light field and to discover new nonclassical effects or states of light field.
基金Project supported by the National Natural Science Foundation of China(Grant No.11404108)
文摘We use quantum field entropy to measure the degree of entanglement for a coherent state light field interacting with two atoms that are initially in an arbitrary two-qubit state. The influence of different mean photon number of the coherent field on the entropy of the field is discussed in detail when the two atoms are initially in one superposition state of the Bell states. The results show that the mean photon number of the light field can regulate the quantum entanglement between the atoms and light field.
基金the National Natural Science Foundation of China(Nos.61774055,51871138,and U2102212)the Science and Technology Committee of Shanghai(No.19010500400)。
文摘Photocatalysis is considered as one of the most promising technologies to generate renewable energy and degrade environmental pollutants.Tremendous efforts have been made to improve photocatalytic efficiency.Among these,tuning spin polarization and introducing an external magnetic field are considered two promising strategies to boost photocatalytic performance.Herein this review highlights the recent breakthroughs through manipulating spin states and applying external magnetic fields for enhancing photocatalytic reactions.The relevant characterization techniques and fundamental mechanisms are summarized.Spin polarization states of photocatalysts have received considerable attention due to their unique roles,including inhibiting the recombination of photoexcited carriers owing to spin orientation constraint,enhancing the reaction product selectivity,and reducing the reaction barriers via optimizing the absorption energy and binding strength.As for the effects of external magnetic field on photocatalytic performance,we mainly discuss the separation enhancement of photoinduced carriers under static and time-varying magnetic fields and the magneto-hydrodynamic effect of charged particles.Lastly,the negative magnetoresistance effect is discussed due to the synergistic effects of the electron spin state and an external magnetic field.These discussions in this review may provide new insights into designing new semiconductors for boosting photocatalytic performance in internal and external magnetic fields.
