The spatial-temporal relationship between high-quality source rocks and reservoirs is a key factor when evaluating the formation,occurrence,and prospectivity of tight oil and gas reservoirs.In this study,we analyze th...The spatial-temporal relationship between high-quality source rocks and reservoirs is a key factor when evaluating the formation,occurrence,and prospectivity of tight oil and gas reservoirs.In this study,we analyze the fundamental oil and gas accumulation processes occurring in the Songliao Basin,contrasting tight oil sand reservoirs in the south with tight gas sand reservoirs in the north.This is done using geochemical data,constant-rate and conventional mercury injection experiments,and fluid inclusion analyses.Our results demonstrate that as far as fluid mobility is concerned,the expulsion center coincides with the overpressure zone,and its boundary limits the occurrence of tight oil and gas accumulations.In addition,the lower permeability limit of high-quality reservoirs,controlled by pore-throat structures,is 0.1×10^-3μm^2 in the fourth member of the Lower Cretaceous Quantou Formation(K1q^4)in the southern Songliao Basin,and 0.05×10^-3μm^2 in the Lower Cretaceous Shahezi Formation(K1sh)in the northern Songliao Basin.Furthermore,the results indicate that the formation of tight oil and gas reservoirs requires the densification of reservoirs prior to the main phase of hydrocarbon expulsion from the source rocks.Reservoir“sweet spots”develop at the intersection of high-quality source rocks(with high pore pressure)and reservoirs(with high permeability).展开更多
The theory of ＂source rock control＂ has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accu...The theory of ＂source rock control＂ has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not？ What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon （oil） expulsion, which is calculated by the material balance principle, versus total organic carbon （TOC）. The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks： those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K^n2 and K^n~ of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion, respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.展开更多
The characteristics and formation mechanisms of the mixed siliciclastic-carbonate reservoirs of the Paleogene Shahejie Formation in the central Bohai Sea were examined based on polarized light microscopy and scanning ...The characteristics and formation mechanisms of the mixed siliciclastic-carbonate reservoirs of the Paleogene Shahejie Formation in the central Bohai Sea were examined based on polarized light microscopy and scanning electron microscopy observations, X-ray diffrac- tometry, carbon and oxygen stable isotope geochemistry, and integrated fluid inclusion analysis. High-quality reservoirs are mainly distributed in Type I and Type II mixed siliciclastic-carbonate sediments, and the dominant pore types include residual primary intergranular pores and intrafossil pores, feldspar dissolution pores mainly devel- oped in Type II sediments. Type I mixed sediments are characterized by precipitation of early pore-lining dolo- mite, relatively weak mechanical compaction during deep burial, and the occurrence of abundant oil inclusions in high-quality reservoirs. Microfacies played a critical role in the formation of the mixed reservoirs, and high-quality reservoirs are commonly found in high-energy environ- ments, such as fan delta underwater distributary channels, mouth bars, and submarine uplift beach bars. Abundant intrafossil pores were formed by bioclastic decay, and secondary pores due to feldspar dissolution further enhance reservoir porosity. Mechanical compaction was inhibited by the precipitation of pore-lining dolomite formed during early stage, and oil emplacement has further led to the preservation of good reservoir quality.展开更多
The 19th National Congress of the Communist Party of China has proposed a national strategy for a healthy China,which includes the formulation of a new plan to promote high-quality development.Oral diseases have been ...The 19th National Congress of the Communist Party of China has proposed a national strategy for a healthy China,which includes the formulation of a new plan to promote high-quality development.Oral diseases have been included in the national“Medium-and Long-term Plan for the Prevention and Treatment of Chronic Diseases”.Chinas national oral health strategy provides great opportunities for advancements in stomatology and for the improvement of the people s oral health.This article discusses these opportunities for advancement in the field of stomatology in China from six aspects:societal needs of oral health;advances in science and technology;changed diagnosis and treatment modes;application of big data;multidistiplinary integration;and talent training.展开更多
Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flex...Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices, while it is a very challenging work, and usually amorphous, polycrystalline or discontinuous single crystalline films are achieved. Here we demonstrate the direct growth of high-quality Bi2 Te3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique. Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film, although amounts of disoriented crystallites are generated due to fast growth rate. By inserting a quartz filter into the growth tube, the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction. Furthermore, flexible Bi2 Te3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending, which also confirms the obtained fexible films suitable for electronic applications.展开更多
The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heteroju...The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics perspectives.Kinetics analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions migration.The small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on heterointerface.Consequently,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is presented.This work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.展开更多
We report a reproducible approach in preparing high-quality overdoped Bi2 Sr2 CaCu2 08＋δ （Bi2212） single crystals by annealing Bi2212 crystals in high oxygen pressure followed by a fast quenching. In this way, hig...We report a reproducible approach in preparing high-quality overdoped Bi2 Sr2 CaCu2 08＋δ （Bi2212） single crystals by annealing Bi2212 crystals in high oxygen pressure followed by a fast quenching. In this way, high-quality overdoped and heavily overdoped Bi2212 single crystals are obtained by controlling the annealing oxygen pressure. We find that, beyond a limit of oxygen pressure that can achieve most heavily overdoped Bi2212 with a Tc N63 K, the annealed Bi2212 begins to decompose. This accounts for the existence of the hole-doping limit and thus the Tc limit in the heavily overdoped region of Bi2212 by the oxygen annealing process. These results provide a reliable way in preparing high-quality overdoped and heavily overdoped Bi2212 crystals that are important for studies of the physical properties, electronic structure and superconductivity mechanism of the cuprate superconductors.展开更多
We study the effect of the AlGaN interlayer on structural quality and strain engineering of the GaN films grown on SiC substrates with an AlN buffer layer, hnproved structural quality and tensile stress releasing are ...We study the effect of the AlGaN interlayer on structural quality and strain engineering of the GaN films grown on SiC substrates with an AlN buffer layer, hnproved structural quality and tensile stress releasing are realized in unintentionally doped GaN thin films grown on 6H-SiC substrates by metal organic chemical vapor deposition. Using the optimized AlGaN interlayer, we find that the full width at half maximum of x-ray diffraction peaks for GaN decreases dramatically, indicating an improved crystalline quality. Meanwhile, it is revealed that the biaxial tensile stress in the GaN film is significantly reduced from the Raman results. Photoluminescence spectra exhibit a shift of the peak position of the near-band-edge emission, as well as the integrated intensity ratio variation of the near-band-edge emission to the yellow luminescence band. Thus by optimizing the AlGaN interlayer, we could acquire the high-quality and strain-relaxation GaN epilayer with large thickness on SiC substrates.展开更多
Using a three-stage hydrogenation process, high-quality 150 bright stock (150BS) was produced from light DAO (LDAO, light deasphalted oil), which was obtained from vacuum residue of heavy naphthenic crude oil of Zo...Using a three-stage hydrogenation process, high-quality 150 bright stock (150BS) was produced from light DAO (LDAO, light deasphalted oil), which was obtained from vacuum residue of heavy naphthenic crude oil of Zone No.9 in Xinjiang. The 150BS product, whose viscosity index is greater than 90, is colorless and has good viscosity-temperature characteristics. This product turns out to be an excellent blending component of high-grade engine oil. And with the 150BS as a feed, very high-viscosity white oil was also produced by a further hydrofining step to substantially reduce the amount of polyaromatics contained in the feed.展开更多
High-quality superconducting FeSe0.5 Te0.5 films are epitaxiMly grown on different substrates by using the pulsed laser deposition method. By measuring the transport properties and surface morphology of films grown on...High-quality superconducting FeSe0.5 Te0.5 films are epitaxiMly grown on different substrates by using the pulsed laser deposition method. By measuring the transport properties and surface morphology of films grown on single- crystal substrates of Al2O3 （0001）, SrTiO3 （001）, and MgO （001）, as well as monitoring the real-time growth process on MgO substrates with reflection high energy electron diffraction, we find the appropriate parameters for epitaxial growth of high-quality FeSe0.5 Te0.5 thin films suitable for angle-resolved photoemission spectroscopy measurements. We further report the angle-resolved photoemission spectroscopy characterization of the super- conducting films. The clearly resolved Fermi surfaces and the band structure suggest a sample quality that is as good as that of high-quality single-crystals, demonstrating that the pulsed laser deposition method can serve as a promising technique for in situ preparation and manipulation of iron-based superconducting thin films, which may bring new prosperity to angle-resolved photoemission spectroscopy research on iron-based superconductors.展开更多
It is shown that the introduction of thermal effect, zero-point vibration, and phonon anharmonicity to a high quality and first-principle-Sased force field （atomic potential） results in a significant improvement in ...It is shown that the introduction of thermal effect, zero-point vibration, and phonon anharmonicity to a high quality and first-principle-Sased force field （atomic potential） results in a significant improvement in predict- ing the densities for the α phase crystalline hexahydro-1,3,5-trinitro-l,3,5-triazine （RDX）, and derivation of its high-fidelity Hugoniot locus and Mie-Grfineisen equation of state covering a very wide range of pressures and temperatures. This work can be used to efficiently and accurately predict the thermophysical properties of solid explosives over the pressures and temperatures to which they are subjected, which is a long-standing issue in the field of energetic materials.展开更多
A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest gra...A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 /μm for substrate temperature at 300 ℃ and annealed at 550℃ for 3 hours.展开更多
In order to promote the high-quality development of textile industry, promote the deep integration of Internet, big data, artificial intelligence and textile industry, and accelerate the innovative application of indu...In order to promote the high-quality development of textile industry, promote the deep integration of Internet, big data, artificial intelligence and textile industry, and accelerate the innovative application of industrial Internet in textile industry. On June 23rd, the first China Textile 4.0 Forum was held in Keqiao in 2019. With the theme of “Textile re: invent”, this forum further explores the development path of China’s textile industry Internet and helps China to realize a strong textile industry. The conference is guided by China National Textile and Apparel Council, hosted by China Textile Industry Internet Alliance, China Textile Enterprise Association, supported by the People’s Government of Keqiao District, Shaoxing City, organized by Keqiao District Bureau of Economy and Information Technology, Huansi Intelligent Technology Inc. and co-organized by Beijing Shuzhi.AI Co., Ltd. Operate from a strategically advantageous position, the future is promising Textile industry is a traditional pillar industry, an important livelihood industry and an industry that creates new international advantages. Since the reform and opening up, the development of textile industry has made remarkable achievements, and realized the great transformation of the industry from small to large and from big to strong. At present, China’s economy has changed from the stage of high-speed growth to the stage of high-quality development. How to transform and upgrade the textile industry to achieve high-quality development, and to transform into innovation-driven science and technology industry, responsibility-oriented green industry and culture-led fashion industry has become an important proposition of the times.展开更多
On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awa...On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awards of the National Textile Industry were held in Beijing.展开更多
We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by ...We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by transforming the Bloch wave number from the translational periodic system.We extensively classify and study these BICs and BCR modes,which exhibit high-quality(high-Q)factors,in different regions relative to the interface of the system.These BICs and BCR modes with a high-Q factor have been studied in detail based on distinctive structural parameters and scattering theory.The outcomes of this research break the periodic limitation of interface state-based BICs,and realize more and higher symmetry interface state-based BICs and BCR modes.Moreover,we can control the region where light is captured by adjusting the frequency,and show that the Q factor of BICs is more closely related to the ordinal number of rings and the rotational symmetry number of the system.展开更多
Weiyuan shale gas play is characterized by thin high-quality reservoir thickness,big horizontal stress difference,and big productivity differences between wells.Based on integrated evaluation of shale gas reservoir ge...Weiyuan shale gas play is characterized by thin high-quality reservoir thickness,big horizontal stress difference,and big productivity differences between wells.Based on integrated evaluation of shale gas reservoir geology and well logging interpretation of more than 20 appraisal wells,a correlation was built between the single well test production rate and the high-quality reservoir length drilled in the horizontal wells,high-quality reservoir thickness and the stimulation treatment parameters in over 100 horizontal wells,the dominating factors on horizontal well productivity were found out,and optimized development strategies were proposed.The results show that the deployed reserves of high-quality reservoir are the dominating factors on horizontal well productivity.In other words,the shale gas well productivity is controlled by the thickness of the high-quality reservoir,the high-quality reservoir drilling length and the effectiveness of stimulation.Based on the above understanding,the development strategies in Weiyuan shale gas play are optimized as follows:(1)The target of horizontal wells is located in the middle and lower parts of Longyi 11(Wei202 area)and Longyi 11(Wei204 area).(2)Producing wells are drilled in priority in the surrounding areas of Weiyuan county with thick high-quality reservoir.(3)A medium to high intensity stimulation is adopted.After the implementation of these strategies,both the production rate and the estimated ultimate recovery(EUR)of individual shale gas wells have increased substantially.展开更多
Purpose: The number of citations has been widely used to measure the significance of a paper. However, there is a need in introducing another index to determine superiority or inferiority of papers with the same numbe...Purpose: The number of citations has been widely used to measure the significance of a paper. However, there is a need in introducing another index to determine superiority or inferiority of papers with the same number of citations. We determine superiority or inferiority of papers by using the ranking based on the number of citations and PageRank.Design/methodology/approach: We show the positive linear correlation between Citation Rank(the ranking of the number of citation) and PageRank. On this basis, we identify highquality, prestige, emerging, and popular papers. Findings: We found that the high-quality papers belong to the subjects of biochemistry and molecular biology, chemistry, and multidisciplinary sciences. The prestige papers correspond to the subjects of computer science, engineering, and information science. The emerging papers are related to biochemistry and molecular biology, as well as those published in the journal "Cell." The popular papers belong to the subject of multidisciplinary sciences. Research limitations: We analyze the Science Citation Index Expanded(SCIE) from 1981 to 2015 to calculate Citation Rank and PageRank within a citation network consisting of 34,666,719 papers and 591,321,826 citations.Practical implications: Our method is applicable to forecast emerging fields of research subjects in science and helps policymakers to consider science policy.Originality/value: We calculated PageRank for a giant citation network which is extremely larger than the citation networks investigated by previous researchers.展开更多
The global trend towards carbon reduction,energy conservation,and sustainable use of resources has led to an increased focus on the use of waste sludge in construction.We used waste sludge from a reservoir to produce ...The global trend towards carbon reduction,energy conservation,and sustainable use of resources has led to an increased focus on the use of waste sludge in construction.We used waste sludge from a reservoir to produce high-strength sintered lightweight aggregate,and then used the densified mixture design algorithm to create high-performance concrete from the sintered aggregate with only small amounts of mixing water and cement.Ultrasonic,electrical resistance and concrete strength efficiency tests were perfo...展开更多
The reservoir properties, diagenetic features and evolution of the Paleogene Shahejie Formation(Es) in the Nanpu sag, Bohai Bay Basin were analyzed based on mineralogical and petrological data, and the main controllin...The reservoir properties, diagenetic features and evolution of the Paleogene Shahejie Formation(Es) in the Nanpu sag, Bohai Bay Basin were analyzed based on mineralogical and petrological data, and the main controlling factors and formation mechanisms of medium to deep high-quality reservoir were revealed by multiple regression analysis. The results show that the sedimentary microfacies, rigid grains content, and dissolution process are the key factors controlling the formation of high-quality clastic reservoir in middle to deep depth in the Nanpu sag. The formation mechanisms of middle to deep sandstones of the Es in different structural belts differ widely in formation mechanism. The Es1(uppermost member of Es) sandstone reservoirs in the Nanpu No.3 structural belt is low porosity, moderate to high permeability reservoir in the mesodiagenesis A2 stage on the whole, and the formation of high-quality reservoirs is mainly attributed to strong compaction resistance ability primarily, and dissolution process secondarily. The Es3(third member of Es) sandstones in Gaoshangpu structural belt is classified as tight sandstones in the mesodiagenesis A1 stage, in which the development of favorable reservoirs is primarily controlled by dissolution. This study provides references for reservoir evaluation of deep clastic reservoirs and exploration deployment in the Bohai Bay rift basin. As there are high-quality reservoirs, it is believed that the deep clastic reservoirs in the eastern of China, such as Bohai Bay Basin still have significant exploration potential.展开更多
GaN intermedial layers grown under different pressures are inserted between GaN epilayers and AIN/Si（111） substrates. In situ optical reflectivity measurements show that a transition from the three-dimensional （3D...GaN intermedial layers grown under different pressures are inserted between GaN epilayers and AIN/Si（111） substrates. In situ optical reflectivity measurements show that a transition from the three-dimensional （3D） mode to the 2I） one occurs during the GaN epilayer growth when a higher growth pressure is used during the preceding GaN intermedial layer growth, and an improvement of the crystalline quality of GaN epilayer will be made. Combining the in situ reflectivity and transmission electron microscopy （TEM） measurements, it is suggested that the lateral growth at the transition of growth mode is favourable for bending of dislocation lines, thus reducing the density of threading dislocations in the epilayer.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 41210005 and 41776081)the National Oil and Gas Major Project of China (No. 2011ZX05007-001)the Applied Basic Research Program of Qingdao (No. 2016239)
文摘The spatial-temporal relationship between high-quality source rocks and reservoirs is a key factor when evaluating the formation,occurrence,and prospectivity of tight oil and gas reservoirs.In this study,we analyze the fundamental oil and gas accumulation processes occurring in the Songliao Basin,contrasting tight oil sand reservoirs in the south with tight gas sand reservoirs in the north.This is done using geochemical data,constant-rate and conventional mercury injection experiments,and fluid inclusion analyses.Our results demonstrate that as far as fluid mobility is concerned,the expulsion center coincides with the overpressure zone,and its boundary limits the occurrence of tight oil and gas accumulations.In addition,the lower permeability limit of high-quality reservoirs,controlled by pore-throat structures,is 0.1×10^-3μm^2 in the fourth member of the Lower Cretaceous Quantou Formation(K1q^4)in the southern Songliao Basin,and 0.05×10^-3μm^2 in the Lower Cretaceous Shahezi Formation(K1sh)in the northern Songliao Basin.Furthermore,the results indicate that the formation of tight oil and gas reservoirs requires the densification of reservoirs prior to the main phase of hydrocarbon expulsion from the source rocks.Reservoir“sweet spots”develop at the intersection of high-quality source rocks(with high pore pressure)and reservoirs(with high permeability).
基金funded by the 973 Prophase Special Program of China(NO.2011CB211701)National Natural Science Foundation of China(41172134)CNPC Innovation Foundation (2011D-5006-0101)
文摘The theory of ＂source rock control＂ has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not？ What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon （oil） expulsion, which is calculated by the material balance principle, versus total organic carbon （TOC）. The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks： those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K^n2 and K^n~ of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion, respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.
基金financially supported by the National Science & Technology Specific Project (Grant No. 2011ZX05023-006)
文摘The characteristics and formation mechanisms of the mixed siliciclastic-carbonate reservoirs of the Paleogene Shahejie Formation in the central Bohai Sea were examined based on polarized light microscopy and scanning electron microscopy observations, X-ray diffrac- tometry, carbon and oxygen stable isotope geochemistry, and integrated fluid inclusion analysis. High-quality reservoirs are mainly distributed in Type I and Type II mixed siliciclastic-carbonate sediments, and the dominant pore types include residual primary intergranular pores and intrafossil pores, feldspar dissolution pores mainly devel- oped in Type II sediments. Type I mixed sediments are characterized by precipitation of early pore-lining dolo- mite, relatively weak mechanical compaction during deep burial, and the occurrence of abundant oil inclusions in high-quality reservoirs. Microfacies played a critical role in the formation of the mixed reservoirs, and high-quality reservoirs are commonly found in high-energy environ- ments, such as fan delta underwater distributary channels, mouth bars, and submarine uplift beach bars. Abundant intrafossil pores were formed by bioclastic decay, and secondary pores due to feldspar dissolution further enhance reservoir porosity. Mechanical compaction was inhibited by the precipitation of pore-lining dolomite formed during early stage, and oil emplacement has further led to the preservation of good reservoir quality.
文摘The 19th National Congress of the Communist Party of China has proposed a national strategy for a healthy China,which includes the formulation of a new plan to promote high-quality development.Oral diseases have been included in the national“Medium-and Long-term Plan for the Prevention and Treatment of Chronic Diseases”.Chinas national oral health strategy provides great opportunities for advancements in stomatology and for the improvement of the people s oral health.This article discusses these opportunities for advancement in the field of stomatology in China from six aspects:societal needs of oral health;advances in science and technology;changed diagnosis and treatment modes;application of big data;multidistiplinary integration;and talent training.
基金Supported by the National Basic Research Program of China under Grant No 2012CB619200the National Natural Science Foundation of China under Grant Nos 61290304,11074265 and 11174307+1 种基金the Natural Science Foundation of Shanghai under Grant No 16ZR1441200the Frontier Science Research Project(Key Programs)of Chinese Academy of Sciences under Grant No QYZDJ-SSW-SLH018
文摘Recently, great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products. Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices, while it is a very challenging work, and usually amorphous, polycrystalline or discontinuous single crystalline films are achieved. Here we demonstrate the direct growth of high-quality Bi2 Te3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique. Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film, although amounts of disoriented crystallites are generated due to fast growth rate. By inserting a quartz filter into the growth tube, the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction. Furthermore, flexible Bi2 Te3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending, which also confirms the obtained fexible films suitable for electronic applications.
基金supported by the Beijing Natural Science Founding (2202050)the Beijing Institute of Technology scientific cooperation project (BITBLR2020010)+1 种基金the National Nature Science Foundation of China (21111120074)the National Nature Science Foundation of China (20806008)。
文摘The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics perspectives.Kinetics analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions migration.The small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on heterointerface.Consequently,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is presented.This work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11190022,11334010 and 11534007the National Basic Research Program of China under Grant No 2015CB921000the Strategic Priority Research Program(B)of Chinese Academy of Sciences under Grant No XDB07020300
文摘We report a reproducible approach in preparing high-quality overdoped Bi2 Sr2 CaCu2 08＋δ （Bi2212） single crystals by annealing Bi2212 crystals in high oxygen pressure followed by a fast quenching. In this way, high-quality overdoped and heavily overdoped Bi2212 single crystals are obtained by controlling the annealing oxygen pressure. We find that, beyond a limit of oxygen pressure that can achieve most heavily overdoped Bi2212 with a Tc N63 K, the annealed Bi2212 begins to decompose. This accounts for the existence of the hole-doping limit and thus the Tc limit in the heavily overdoped region of Bi2212 by the oxygen annealing process. These results provide a reliable way in preparing high-quality overdoped and heavily overdoped Bi2212 crystals that are important for studies of the physical properties, electronic structure and superconductivity mechanism of the cuprate superconductors.
基金Supported by the National Key R&D Program of China under Grant No 2016YFB0400200
文摘We study the effect of the AlGaN interlayer on structural quality and strain engineering of the GaN films grown on SiC substrates with an AlN buffer layer, hnproved structural quality and tensile stress releasing are realized in unintentionally doped GaN thin films grown on 6H-SiC substrates by metal organic chemical vapor deposition. Using the optimized AlGaN interlayer, we find that the full width at half maximum of x-ray diffraction peaks for GaN decreases dramatically, indicating an improved crystalline quality. Meanwhile, it is revealed that the biaxial tensile stress in the GaN film is significantly reduced from the Raman results. Photoluminescence spectra exhibit a shift of the peak position of the near-band-edge emission, as well as the integrated intensity ratio variation of the near-band-edge emission to the yellow luminescence band. Thus by optimizing the AlGaN interlayer, we could acquire the high-quality and strain-relaxation GaN epilayer with large thickness on SiC substrates.
文摘Using a three-stage hydrogenation process, high-quality 150 bright stock (150BS) was produced from light DAO (LDAO, light deasphalted oil), which was obtained from vacuum residue of heavy naphthenic crude oil of Zone No.9 in Xinjiang. The 150BS product, whose viscosity index is greater than 90, is colorless and has good viscosity-temperature characteristics. This product turns out to be an excellent blending component of high-grade engine oil. And with the 150BS as a feed, very high-viscosity white oil was also produced by a further hydrofining step to substantially reduce the amount of polyaromatics contained in the feed.
基金Supported by the Chinese Academy of Sciences under Grant No 2010Y1JB6the National Basic Research Program of China under Grant No 2010CB923000the National Natural Science Foundation of China under Grant Nos 11234014 and 11227903
文摘High-quality superconducting FeSe0.5 Te0.5 films are epitaxiMly grown on different substrates by using the pulsed laser deposition method. By measuring the transport properties and surface morphology of films grown on single- crystal substrates of Al2O3 （0001）, SrTiO3 （001）, and MgO （001）, as well as monitoring the real-time growth process on MgO substrates with reflection high energy electron diffraction, we find the appropriate parameters for epitaxial growth of high-quality FeSe0.5 Te0.5 thin films suitable for angle-resolved photoemission spectroscopy measurements. We further report the angle-resolved photoemission spectroscopy characterization of the super- conducting films. The clearly resolved Fermi surfaces and the band structure suggest a sample quality that is as good as that of high-quality single-crystals, demonstrating that the pulsed laser deposition method can serve as a promising technique for in situ preparation and manipulation of iron-based superconducting thin films, which may bring new prosperity to angle-resolved photoemission spectroscopy research on iron-based superconductors.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11372053,11402031,11221202 and 11172044the Opening Project of the State Key Laboratory of Explosion Science and Technology under Grant No KFJJ14-06M
文摘It is shown that the introduction of thermal effect, zero-point vibration, and phonon anharmonicity to a high quality and first-principle-Sased force field （atomic potential） results in a significant improvement in predict- ing the densities for the α phase crystalline hexahydro-1,3,5-trinitro-l,3,5-triazine （RDX）, and derivation of its high-fidelity Hugoniot locus and Mie-Grfineisen equation of state covering a very wide range of pressures and temperatures. This work can be used to efficiently and accurately predict the thermophysical properties of solid explosives over the pressures and temperatures to which they are subjected, which is a long-standing issue in the field of energetic materials.
基金This work was supported by the Guangdong Provincial Natural Science Foundation of China No.990781.
文摘A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 /μm for substrate temperature at 300 ℃ and annealed at 550℃ for 3 hours.
文摘In order to promote the high-quality development of textile industry, promote the deep integration of Internet, big data, artificial intelligence and textile industry, and accelerate the innovative application of industrial Internet in textile industry. On June 23rd, the first China Textile 4.0 Forum was held in Keqiao in 2019. With the theme of “Textile re: invent”, this forum further explores the development path of China’s textile industry Internet and helps China to realize a strong textile industry. The conference is guided by China National Textile and Apparel Council, hosted by China Textile Industry Internet Alliance, China Textile Enterprise Association, supported by the People’s Government of Keqiao District, Shaoxing City, organized by Keqiao District Bureau of Economy and Information Technology, Huansi Intelligent Technology Inc. and co-organized by Beijing Shuzhi.AI Co., Ltd. Operate from a strategically advantageous position, the future is promising Textile industry is a traditional pillar industry, an important livelihood industry and an industry that creates new international advantages. Since the reform and opening up, the development of textile industry has made remarkable achievements, and realized the great transformation of the industry from small to large and from big to strong. At present, China’s economy has changed from the stage of high-speed growth to the stage of high-quality development. How to transform and upgrade the textile industry to achieve high-quality development, and to transform into innovation-driven science and technology industry, responsibility-oriented green industry and culture-led fashion industry has become an important proposition of the times.
文摘On January 21,the 13th Annual China Textile Roundtable,"Shuyang Cup"·The 6th China Textile News Award Ceremony,and the First Award Ceremony of the Qualified Enterprises for the Review of the Quality Awards of the National Textile Industry were held in Beijing.
基金supported by the National Natural Science Foundation of China (Grant Nos.61405058 and 62075059)the Natural Science Foundation of Hunan Province (Grant Nos.2017JJ2048 and 2020JJ4161)+2 种基金the Scientific Research Foundation of Hunan Provincial Education Department (Grant No.21A0013)the Open Project of State Key Laboratory of Advanced Optical Communication Systems and Networks of China (Grant No.2024GZKF20)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2024A1515011353)。
文摘We have introduced a new approach to calculate the orbital angular momentum(OAM)of bound states in continuum(BICs)and below-continuum-resonance(BCR)modes in the rotational periodic system nested inside and outside by transforming the Bloch wave number from the translational periodic system.We extensively classify and study these BICs and BCR modes,which exhibit high-quality(high-Q)factors,in different regions relative to the interface of the system.These BICs and BCR modes with a high-Q factor have been studied in detail based on distinctive structural parameters and scattering theory.The outcomes of this research break the periodic limitation of interface state-based BICs,and realize more and higher symmetry interface state-based BICs and BCR modes.Moreover,we can control the region where light is captured by adjusting the frequency,and show that the Q factor of BICs is more closely related to the ordinal number of rings and the rotational symmetry number of the system.
文摘Weiyuan shale gas play is characterized by thin high-quality reservoir thickness,big horizontal stress difference,and big productivity differences between wells.Based on integrated evaluation of shale gas reservoir geology and well logging interpretation of more than 20 appraisal wells,a correlation was built between the single well test production rate and the high-quality reservoir length drilled in the horizontal wells,high-quality reservoir thickness and the stimulation treatment parameters in over 100 horizontal wells,the dominating factors on horizontal well productivity were found out,and optimized development strategies were proposed.The results show that the deployed reserves of high-quality reservoir are the dominating factors on horizontal well productivity.In other words,the shale gas well productivity is controlled by the thickness of the high-quality reservoir,the high-quality reservoir drilling length and the effectiveness of stimulation.Based on the above understanding,the development strategies in Weiyuan shale gas play are optimized as follows:(1)The target of horizontal wells is located in the middle and lower parts of Longyi 11(Wei202 area)and Longyi 11(Wei204 area).(2)Producing wells are drilled in priority in the surrounding areas of Weiyuan county with thick high-quality reservoir.(3)A medium to high intensity stimulation is adopted.After the implementation of these strategies,both the production rate and the estimated ultimate recovery(EUR)of individual shale gas wells have increased substantially.
基金supported by Nihon University College of Science and Technology Grants-in Aid 2012 and 2016。
文摘Purpose: The number of citations has been widely used to measure the significance of a paper. However, there is a need in introducing another index to determine superiority or inferiority of papers with the same number of citations. We determine superiority or inferiority of papers by using the ranking based on the number of citations and PageRank.Design/methodology/approach: We show the positive linear correlation between Citation Rank(the ranking of the number of citation) and PageRank. On this basis, we identify highquality, prestige, emerging, and popular papers. Findings: We found that the high-quality papers belong to the subjects of biochemistry and molecular biology, chemistry, and multidisciplinary sciences. The prestige papers correspond to the subjects of computer science, engineering, and information science. The emerging papers are related to biochemistry and molecular biology, as well as those published in the journal "Cell." The popular papers belong to the subject of multidisciplinary sciences. Research limitations: We analyze the Science Citation Index Expanded(SCIE) from 1981 to 2015 to calculate Citation Rank and PageRank within a citation network consisting of 34,666,719 papers and 591,321,826 citations.Practical implications: Our method is applicable to forecast emerging fields of research subjects in science and helps policymakers to consider science policy.Originality/value: We calculated PageRank for a giant citation network which is extremely larger than the citation networks investigated by previous researchers.
文摘The global trend towards carbon reduction,energy conservation,and sustainable use of resources has led to an increased focus on the use of waste sludge in construction.We used waste sludge from a reservoir to produce high-strength sintered lightweight aggregate,and then used the densified mixture design algorithm to create high-performance concrete from the sintered aggregate with only small amounts of mixing water and cement.Ultrasonic,electrical resistance and concrete strength efficiency tests were perfo...
基金Supported by the China National Science and Technology Major Project (2016ZX05006-006)
文摘The reservoir properties, diagenetic features and evolution of the Paleogene Shahejie Formation(Es) in the Nanpu sag, Bohai Bay Basin were analyzed based on mineralogical and petrological data, and the main controlling factors and formation mechanisms of medium to deep high-quality reservoir were revealed by multiple regression analysis. The results show that the sedimentary microfacies, rigid grains content, and dissolution process are the key factors controlling the formation of high-quality clastic reservoir in middle to deep depth in the Nanpu sag. The formation mechanisms of middle to deep sandstones of the Es in different structural belts differ widely in formation mechanism. The Es1(uppermost member of Es) sandstone reservoirs in the Nanpu No.3 structural belt is low porosity, moderate to high permeability reservoir in the mesodiagenesis A2 stage on the whole, and the formation of high-quality reservoirs is mainly attributed to strong compaction resistance ability primarily, and dissolution process secondarily. The Es3(third member of Es) sandstones in Gaoshangpu structural belt is classified as tight sandstones in the mesodiagenesis A1 stage, in which the development of favorable reservoirs is primarily controlled by dissolution. This study provides references for reservoir evaluation of deep clastic reservoirs and exploration deployment in the Bohai Bay rift basin. As there are high-quality reservoirs, it is believed that the deep clastic reservoirs in the eastern of China, such as Bohai Bay Basin still have significant exploration potential.
基金Supported by the National Natural Science Foundation of China under Grant No 60476021.
文摘GaN intermedial layers grown under different pressures are inserted between GaN epilayers and AIN/Si（111） substrates. In situ optical reflectivity measurements show that a transition from the three-dimensional （3D） mode to the 2I） one occurs during the GaN epilayer growth when a higher growth pressure is used during the preceding GaN intermedial layer growth, and an improvement of the crystalline quality of GaN epilayer will be made. Combining the in situ reflectivity and transmission electron microscopy （TEM） measurements, it is suggested that the lateral growth at the transition of growth mode is favourable for bending of dislocation lines, thus reducing the density of threading dislocations in the epilayer.
