Study on fault-controlled hydrocarbon migration and accumulation process and models in Zhu I Depression

Through the analysis of the faults and their internal structure in Zhu I Depression,it is found that the internal structure of the late fault is obviously segmented vertically.It develops unitary structure(simple fault plane)in shallow layers,binary structure(induced fracture zone in hanging wall and sliding fracture zone in footwall)in middle,layers and ternary structure(induced fracture zone in hanging wall and sliding fracture zone in middle,and induced fracture zone in footwall)in deep layers.Because the induced fracture zone is a high porosity and permeability zone,and the sliding fracture zone is a low porosity and ultra-low permeability zone,the late fault in middle layers has the character of"transporting while sealing".The late fault can transport hydrocarbon by its induced fracture zone in the side of the hanging wall and seal hydrocarbon by its sliding fracture zone in the side of the footwall.In deep layers,the late fault has the character of"dual-transportation",induced fracture zones in both sides of hanging wall and footwall can transport hydrocarbon.The early fault that only developed in the deep layers is presumed to be unitary structure,which plays a completely sealing role in the process of hydrocarbon migration and accumulation due to inactivity during the hydrocarbon filling period.Controlled by hydrocarbon source,early/late faults,sand bodies and traps,two reservoir-forming models of"inverted L"and"stereo-spiral"can be proposed in middle layers,while two reservoir-forming models of"cross fault"and"lateral fault sealing"are developed in the deep layers of Zhu I Depression.

Formation Mechanism of Precursor Films at High Temperatures:A Review

The formation of a precursor flm(PF)is always coupled with better wettability;thus,clarifying the formation mechanism is required to optimize the interfacial structures.However,recent research focuses on inert wetting systems at room temperature,which cannot guide practical material processing at high temperatures.In this review,PF formation mechanisms at high temperatures were reviewed.The mechanisms are surface difusion,evaporation–condensation,subcutaneous infltration,and rapid absorption and flm overfow.In experimental metal/metal systems,the most probable mechanism is subcutaneous infltration,related to the apparent contact angle,radius,and height of the gap between the substrate metal and the oxide flm.The rapid absorption and flm overfow mechanism usually occurs in metal/ceramic systems.The PF appearance for the adsorption mechanism must satisfy the paradox,that is,the relative inertial and high-afnity liquid/solid interface.Finally,another possible mechanism of PF appearance for the reactive wetting system at high temperatures was proposed,that is,the thin-surface transport mechanism.The PF formation is sensitive to external conditions.Therefore,it is necessary to develop thermodynamic and dynamic models for predicting and simulating PFs.

Tantalum pentoxide:a new material platform for high-performance dielectric metasurface optics in the ultraviolet and visible region

Dielectric metasurfaces,composed of planar arrays of subwavelength dielectric structures that collectively mimic the operation of conventional bulk optical elements,have revolutionized the field of optics by their potential in constructing high-efficiency and multi-functional optoelectronic systems on chip.The performance of a dielectric metasurface is largely determined by its constituent material,which is highly desired to have a high refractive index,low optical loss and wide bandgap,and at the same time,be fabrication friendly.Here,we present a new material platform based on tantalum pentoxide(Ta2O5)for implementing high-performance dielectric metasurface optics over the ultraviolet and visible spectral region.This wide-bandgap dielectric,exhibiting a high refractive index exceeding 2.1 and negligible extinction coefficient across a broad spectrum,can be easily deposited over large areas with good quality using straightforward physical vapor deposition,and patterned into high-aspect-ratio subwavelength nanostructures through commonly-available fluorine-gas-based reactive ion etching.We implement a series of highefficiency ultraviolet and visible metasurfaces with representative light-field modulation functionalities including polarization-independent high-numerical-aperture lensing,spin-selective hologram projection,and vivid structural color generation,and the devices exhibit operational efficiencies up to 80%.Our work overcomes limitations faced by scalability of commonly-employed metasurface dielectrics and their operation into the visible and ultraviolet spectral range,and provides a novel route towards realization of high-performance,robust and foundry-manufacturable metasurface optics.

Integrating planar photonics for multi-beam generation and atomic clock packaging on chip

The commercialization of atomic technologies requires replacing laboratory-scale laser setups with compact and manufacturable optical platforms.Complex arrangements of free-space beams can be generated on chip through a combination of integrated photonics and metasurface optics.In this work,we combine these two technologies using flip-chip bonding and demonstrate an integrated optical architecture for realizing a compact strontium atomic clock.Our planar design includes twelve beams in two co-aligned magneto-optical traps.These beams are directed above the chip to intersect at a central location with diameters as large as 1 cm.Our design also includes two co-propagating beams at lattice and clock wavelengths.These beams emit collinearly and vertically to probe the center of the magneto-optical trap,where they will have diameters of≈100μm.With these devices we demonstrate that our integrated photonic platform is scalable to an arbitrary number of beams,each with different wavelengths,geometries,and polarizations.

Multifunctional metasurfaces enabled by simultaneous and independent control of phase and amplitude for orthogonal polarization states

Monochromatic light can be characterized by its three fun dame ntal properties:amplitude,phase,and polarization.In this work,we propose a versatile,transmission-mode all-dielectric metasurface platform that can independently manipulate the phase and amplitude for two orthogonal states of polarization in the visible frequency range.For proof-o仁concept experimental demonstration,various single-layer metasurfaces composed of subwavelength-spaced titanium-dioxide nanopillars are designed,fabricated,and characterized to exhibit the ability of polarization-switchable multidimensional light-field manipulation,including polarization-switchable grayscale nanoprinting,nonuniform cylindrical lensing,and complex-amplitude holography.We envision the metasurface platform dem on strated here to open new possibilities toward creating compact multifunctional optical devices for applications in polarization optics,information encoding,optical data storage,and security.

Low-loss metasurface optics down to the deep ultraviolet region

Shrinking conventional optical systems to chip-scale dimensions will benefit custom applications in imaging,displaying,sensing,spectroscopy,and metrology.Towards this goal,metasurfaces-planar arrays of subwavelength electromagnetic structures that collectively mimic the functionality of thicker conventional optical elements-have been exploited at frequencies ranging from the microwave range up to the visible range.Here,we demonstrate highperformance metasurface optical components that operate at ultraviolet wavelengths,including wavelengths down to the record-short deep ultraviolet range,and perform representative wavefront shaping functions,namely,highnumerical-aperture lensing,accelerating beam generation,and hologram projection.The constituent nanostructured elements of the metasurfaces are formed of hafnium oxide-a loss-less,high-refractive-index dielectric material deposited using low-temperature atomic layer deposition and patterned using high-aspect-ratio Damascene lithography.This study opens the way towards low-form factor,multifunctional ultraviolet nanophotonic platforms based on flat optical components,enabling diverse applications including lithography,imaging,spectroscopy,and quantum information processing.

Gas-solid flow in a high-density circulating fluidized bed riser with Geldart group B particles

We carried out experiments to explore and characterize the gas-solid flow dynamics of Geldart group B particles in a dense circulating fluidized bed riser. By reducing the pressure drop across the solid control valve and increasing the solid inventory in the storage tank, a high solid circulation rate and a solid holdup above 0.075 throughout the riser were simultaneously achieved. At a solid-to-gas mass flux ratio of approximately 105, flow transitioned from fast fluidization to a dense suspension upflow. In the axial direction of the riser, solid holdup had an exponential profile, increasing with increasing solid circulation rate and Jot decreasing superficial gas velocity. From the riser＇s center to its wall, the solid holdup increased markedly, exhibiting a steep parabolic profile. Increasing the solid circulation rate increased the radial non-uniformity of the solid concentration, while increasing the superficial gas velocity had the opposite effect, In our dense circulating fluidized bed riser, Geldart group B particles had similar slip characteristics to Geldart group A particles,