Vertical Sequence Research Articles

Integrative Review of the Recent Literature on Human Resilience: From Concepts, Theories, and Discussions Towards a Complex Understanding.

Resilience may be viewed as the capacity of an individual, or perhaps of a dynamic system, to adjust and adapt positively to adversities and disruptions that impact one’s functioning and development. Yet a common statement in the literature is that there are still today numerous ways of defining and conceiving resilience. This multiplicity of approaches calls for clarification and generates a need of common theoretical ground. Therefore, this review aims to examine, to clarify and to synthesize how “human” resilience is conceptualized within the recent human sciences literature to help answer the question: ‘What are the key approaches, concepts, and definitions of resilience?”. Following Whittemore and Knafl (2005, https://doi.org/10.1111/j.1365-2648.2005.03621.x) methods, an integrative review of the recent resilience literature (2013–2019) was undertaken. Four databases were used for the search: PsycINFO, PubMed, ERIC, Google Scholar. A reference and citation tracking was then performed on the papers identified. Sixty-nine papers passed all the stages (identification, screening, eligibility, inclusion) and formed the sample. Results show that resilience definitions are nowadays either about “adapting and bouncing back to previous levels of health” or about “thriving and rising above the adversity towards increased levels of health.” Results also show that resilience features—antecedents, mechanisms, consequences—are mainly conceptualized in a vertical sequence where an antecedent influences another or influences a mechanism leading to consequences. This paper concludes that modern conceptions can fit within a transactional and constructivist approach that goes beyond the former approaches by providing a more nuanced and realistic picture of the resilience process and by viewing it as a dynamic and person-situation-defined process.

Articulation in English Language Curricula: A Systematic Analysis from Basic Education to Secondary Education

Despite many studies on English language curricula over the last two decades in Turkey, any analysis of articulation in the curricula has not been found. Articulation, which addresses the inter-relatedness of a curriculum in many ways, both vertically and horizontally, ensures planning of student's development holistically and the transfer of learning from one education level to another. In this study, basic education and secondary education English language curricula published in 2018 were systematically examined in terms of articulation by looking for an answer to the question "To what extent do the English curricula attain the horizontal and vertical across the school levels?" specifically. Guideline Questions for Determining Articulation which were developed through the literature review and expert opinions, were used in the study adopting a document analysis. The data were analyzed according to descriptive analysis. The findings display that the English language curricula from basic education to secondary education reflect the culture of the target language in a very limited way and that the interdisciplinarity of the curricula is weak. Therefore, it is concluded that the curricula have attained horizontal articulation partially. In terms of vertical articulation, although continuity and sequence across the grades are mostly achieved, the study uncovered the problems about the assessment of four skills in an integrated way, the progress of learning outcomes from lower-to higher-order thinking skills, the coordination of the language proficiency aimed as the final outcome at the school levels as well as the assessment of them. Consequently, the study revealed that both the horizontal and vertical (especially across the school levels) articulation of the curricula are not fully ensured. Various implications have been made to strengthen the articulation of English language curricula.

Sliding ferroelectricity in 2D van der Waals materials: Related physics and future opportunities

Near the 100th anniversary of the discovery of ferroelectricity, so-called sliding ferroelectricity has been proposed and confirmed recently in a series of experiments that have stimulated remarkable interest. Such ferroelectricity exists widely and exists only in two-dimensional (2D) van der Waals stacked layers, where the vertical electric polarization is switched by in-plane interlayer sliding. Reciprocally, interlayer sliding and the “ripplocation” domain wall can be driven by an external vertical electric field. The unique combination of intralayer stiffness and interlayer slipperiness of 2D van der Waals layers greatly facilitates such switching while still maintaining environmental and mechanical robustness at ambient conditions. In this perspective, we discuss the progress and future opportunities in this behavior. The origin of such ferroelectricity as well as a general rule for judging its existence are summarized, where the vertical stacking sequence is crucial for its formation. This discovery broadens 2D ferroelectrics from very few material candidates to most of the known 2D materials. Their low switching barriers enable high-speed data writing with low energy cost. Related physics like Moiré ferroelectricity, the ferroelectric nonlinear anomalous Hall effect, and multiferroic coupling are discussed. For 2D valleytronics, nontrivial band topology and superconductivity, their possible couplings with sliding ferroelectricity via certain stacking or Moiré ferroelectricity also deserve interest. We provide critical reviews on the current challenges in this emerging area.

Varves in the Yixian Formation, western Liaoning: Constraining the palaeoclimate in the Early Cretaceous

The study of the palaeoenvironment of the Early Cretaceous has been a significant research topic, largely due to the “Jehol Biota” in western Liaoning and the important prospect of fossils in Dakangpu Layer. Based on the sedimentology of Dakangpu Layer, it is helpful to get a deeper understanding of the living environment of the “Jehol Biota.” Varves are highly developed in the Dakangpu Bed of lower Cretaceous Yixian Basin in western Liaoning, China, supplying reliable and high‐quality proxies to explore the palaeoclimate. This paper reconstructs the palaeo‐lake environment and palaeoclimate, using petrography, facies associations, varves components, and geochemistry. Detailed petrographic studies helped to recognize 11 lithofacies which were grouped into two facies associations: Shallow lake and deep to semi‐deep lake sequences. The delicate structure of varves in the Dakangpu Bed were divided into two categories: Clastic and endogenic. Additionally, two sub‐types of clastic varves have been discovered, with distinct components, thickness, and distribution in vertical sequence. Nineteen representative samples of varves reveal that rare earth and trace elements have a similar change trend. The composition, formation, and preservation of the varves in the Dakangpu Bed depicted a deep lake, with stratified water and oxygen‐depleted bottom layer environment. The U/Th ratios and V/Cr ratios are in the ranges of 0.37–1.55 and 0.97–10.47 respectively, supporting the redox environment's minor fluctuation. The varve thickness, flood frequency, sporopollenin collections, and geochemical data indicated that precipitation and humidity decreased gradually in the sedimentary period, and the climate changed to warmer and drier, with fluctuations in the middle to later periods.

Sequence stratigraphy, sedimentary characteristics of barrier coastal sedimentary system of the Benxi Formation (Gaoqiao area, Ordos basin) and favorable reservoir distribution

Benxi Formation is an abundant natural gas reservoir in Gaoqiao area. Therefore, it is essential to analyze the sequence and sedimentary characteristics of the Benxi Formation to predict the distribution of favorable gas reservoirs . After the comprehensive use of the core, thin section, drilling, and logging data, the sequence framework, sedimentary microfacies, planar distribution and vertical microfacies associations of the Benxi formation were studied. The Benxi Formation in the Gaoqiao area is barrier coastal sedimentary system, which is divided into eight sedimentary microfacies, namely, tidal delta, tidal channel, sand flat, mixed flat, mud flat, peat flat, barrier bar, and lagoon mud microfacies. In addition, we concluded that i) From west to east, peat flat, mud flat, mixed flat, sand flat, lagoon mud, and barrier bar have been developed in the study area. ii) Four typical vertical sequences were identified: MA1, MA2, MA1, and MA4. The first three sequences developed extensively and completely in the study area, whereas the last one generally has one or more microfacies missing. iii) The sedimentary system of the Benxi Formation in the Gaoqiao area was primarily vulnerable to tectonism, sequence, and sea-level changes. The Second Member was the target gas-producing stratum of the Formation. Both barrier bar and sand flat microfacies exhibited an excellent gas display. However, the barrier bar microfacies were the most favorable natural gas distribution zones with giant and premium gas reserves.

Lithology recognition of complex carbonatite by deep learning

The formation of carbonate reservoirs is affected by many factors such as sedimentation, diagenesis, and tectonic evolution. The rock composition and pore structures are complex, which brings challenges to the interpretation of reservoir lithology. Therefore, a novel approach of one-dimensional convolutional neural network architecture (1DCNN) based on the optimization of gradient descent algorithm for lithology identification is proposed. By fully combining logging physical parameters and vertical structure sequence context information, the deeper intrinsic rules between reservoir lithology and wireline logs can be found. With feature extracting of multi-scale deep feature extraction from multivariable wireline logs, the ability of wireline logs to express lithological features is improved, and the accuracy of lithological identification is further improved. In order to illustrate the prediction effect, the carbonate reservoir of the Majiagou Formation in Block 41-33 in Sulige Gas Field is taken as an example. The results reveal that 1DCNN improves the accuracy of carbonate lithology identification by 0.95% to 11.16%, which provides a new idea for the recognition of complex carbonate lithology.

K-Mean Clustering Analysis and Logistic Boosting Regression for Rock Facies Characterization and Classification in Zubair Reservoir in Luhais Oil Field, Southern Iraq

Identifying rock facies from petrophysical logs is a crucial step in the evaluation and characterization of hydrocarbon reservoirs. The rock facies can be obtained either from core analysis (lithofacies) or from well logging data (electrofacies). In this research, two advanced machine learning approaches were adopted for electrofacies identification and for lithofacies classification, both given the well-logging interpretations from a well in the upper shale member in Luhais Oil Field, southern Iraq. Specifically, the K-mean partitioning analysis and Logistic Boosting (Logit Boost) were conducted for electrofacies characterization and lithofacies classification, respectively. The dataset includes the routine core analysis of core porosity, core permeability, and measured discrete lithofacies along with the well-logging interpretations include (shale volume, water saturation and effective porosity) given the entire reservoir interval. The K-Mean clustering technique demonstrated good matching between the vertical sequence of identified electrofacies and the observed lithofacies from core description as attained 89.92% total correct percent from the confusion matrix table. The Logit Boost showed excellent matching between the recognized lithofacies from the core description and the predicted lithofacies through attained 98.26% total correct classification rate index from the confusion matrix table. The high accuracy of the Logit Boost algorithm comes from taking into account the non-linearity between the lithofacies and petrophysical properties in the classification process. The high degree of lithofacies classification by Logit Boost in this research can be considered in a similar procedure at all sandstone reservoirs to improve the reservoir characterization. The complete facies identification and classification were implemented with the programming language R, the powerful open-source statistical computing language.

On the Use of Geostatistical Cross-Association Method for Lithostratigraphical Correlation

The aim of this paper is to determine the effectiveness of cross association in detecting the similarity between correlated geological colum- nar sections. For this purpose, cross association is used to compare several geological columnar sections which are arbitrarily selected from different lo- calities in central and north Jordan. It turns out, for most of the study cases, that the sections which consist of the same rock units (formations) are statistically classified as similar (p-value � .05), while sections of differ- ent rock units (formations) are statistically classified as dissimilar (p-value � .05). Geologists get used to study rocks in outcrops or in drill cores. A sequence of sedimentary rocks may be divided up into a number of lithostratigraphical units usually of various sizes. Superimposed lithostratigraphical units are frequently distinguished from each other based on lithological properties and stratigraphical position. The formation is the fundamental unit of stratigraphy with definite lithological composition or a distinctive interbedded or intergraded succession of rock types that must be differ from the adjacent units above and below. The for- mations in a rock sequence named for some geographical localities that show typ- ical exposures of these formations (known as type sections), are usually traceable or mappable from one exposure to another or from well to well in the subsurface (Krumbein and Sloss, 1963; Doyle et al., 1994). Geologists can draw stratigraphi- cal sections for several outcrops (or cores) in an area, and trace beds from section to section that finally leads to what is known as lithological correlation. This type of correlation basically demonstrates the equivalency of rock units across an area. The matter of correlation between different geological sections is relatively easier if the formation in the vertical rock sequence is not so greatly different in its lithology and thickness from one place to another. However, in many cases

Sedimentary processes of shallow-marine turbidite fans: An example from the Huangliu Formation in the Yinggehai Basin, South China Sea

The shallow-marine turbidite fans in the Upper Miocene Huangliu Formation of the Yinggehai Basin in the northwestern South China Sea (SCS) provide an excellent opportunity to understand their sedimentary processes in a shelf depositional environment. The down-slope gravity flow processes and along-slope bottom-current reworking processes of shallow-marine turbidite fans were interpreted by using seismic, well logging, core, petrographic, geochemical, and petrophysical data. Several depositional elements were identified in the shallow-marine turbidite fans, namely, channel-fill high-density turbidites (HDTs), channel-fill low-density turbidites (LDTs) and associated frontal splays, sand-rich/mud-rich lobe deposits, and bottom-current reworked channel-fill/lobe deposits. Deep U-shaped (or V-shaped) seismic reflections and low root-mean-square (RMS) amplitudes characterize the channel-fill HDTs that consist of massive fine-grained sandstones with mud clasts. The channel-fill LDTs, characterized by V-shaped or worm-shaped reflections, mostly consist of normally graded, laminated and rippled, very fine-grained sandstones. Frontal splays are generally associated with channel-fill LDTs. The sand-rich lobe deposits show continuous high-amplitude sheet-like reflections and consist of HDTs and LDTs, whereas the mud-rich lobe deposits show continuous moderate-amplitude reflections and consist of muddy debrites. The bottom-current reworked sandstones (BCRSs), which comprise well-sorted, fine-grained sandstones with traction-current structures, are usually located in the upper parts of thick sandbodies. The variability of depositional elements from large-scale channel-fill HDTs with strong basal erosion in fan-1 to small-scale channel-fill LDTs in fan-2 is closely linked with sea-level fluctuations that result in variable gravity-flow energy and sediment input. However, the reoccurrence of large-scale channel-fill HDTs in fan-3 at sea-level highstands may possibly be attributed to enhanced sediment input from the source areas. Down-slope flow transformation from turbidity flows into muddy debris flows within an individual channel-lobe complex (CLC) resulted in a dramatic increase in clay content and resultant decreasing reservoir quality from the channel-fill HDTs to the mud-rich lobe deposits, because muddy sediments are incorporated into the precursor turbidity flows and turbulence is suppressed. Additionally, it is suggested that the widely developed traction-current structures and tidal signatures (double mud layers, mud-draped ripples, discrete wavy bedding, internal truncation surface, and convex-up laminae) are the products of reworking by internal waves and -tides. During periods of sea-level highstands, the upper parts of gravity-flow sandstones would undergo bottom-current reworking, thus resulting in the retransportation of muddy fines and the formation of reworked sandstones with traction-current structures and tidal signatures. In this study, a combination of traction-current structures, tidal signatures, vertical sequences showing sharp upper contacts and non-gradational upper contacts, and trace elements is considered to be convincing diagnostic criteria in distinguishing reworked sandstones from gravity-flow sandstones. The representative bottom-current reworked sandstones should be preferable hydrocarbon targets in further exploration because of their better reservoir properties compared with gravity-flow sandstones. This research offers some insight into gravity-flow processes and bottom-current reworking processes in a shallow marine environment.

Ice thinning on nunataks during the glacial to interglacial transition in the Antarctic Peninsula region according to Cosmic-Ray Exposure dating: Evidence and uncertainties

The small ice caps distributed across the Antarctic Peninsula region have undergone large ice volume changes since the Last Glacial Cycle, in line with most of the Antarctic continent. While the surface extent of glacial shrinking is relatively well known, the timing of glacial oscillations and the magnitude of ice thinning remain little investigated. Cosmic-Ray Exposure (CRE) dating applied on ice-free vertical sequences can provide insights about the temporal framework of glacial oscillations. However, the potential occurrence of nuclide inheritance may overestimate the real timing of the last glacial retreat. This problem has been observed in many areas in Continental Antarctica, but similar studies have not yet been conducted in environments of the Maritime Antarctica, such as the South Shetland Islands (SSI). This research focuses on the Hurd Peninsula ice cap (HPIC, ca. 60°22′ W, 62°40’ S), located in the SW of Livingston Island, SSI. Past climate oscillations since the Last Glacial Cycle have determined the amount of ice stored in the ice cap. Today, this polythermal ice cap is surrounded by several nunataks standing out above the ice. Three of them have been selected to explore their deglaciation history and to test the potential occurrence of nuclide inheritance in deglaciated bedrocks associated with polythermal glaciers. We present a new dataset with 10 10Be exposure dates. Some of them were found to be anomalously old, evidencing that nuclide inheritance is present in bedrocks associated with polythermal ice caps and suggesting complex glacial exposure histories. We attribute this to limited erosion, given the gentle slope of the nunatak margins and the cold-based character of the surrounding ice. The remaining samples allowed to approach local surface-elevation changes of the HPIC. Our results suggest that ice thinning started during the Last Glacial Maximum (LGM) at ∼22 ka but intense glacial shrinking occurred from ∼18 to ∼13 ka, when the nunataks became exposed, being particularly intense at the end of this period (∼14–13 ka) coinciding with the time of the meltwater pulse 1a (MWP-1a) and the end of the Antarctic Cold Reversal (ACR).

Bach and Busoni Essentials in A Chaotic World

The study analyses the manifestation of structural change from the Bach Violin Chaconne (BWV1004, c.1720) to the Bach-Busoni piano transcription (c.1897). This article explores the use of two-dimensional music abstraction for vertical (pitch height) and horizontal (time) and its signal insignificant identified bariolage sections in music. Bariolage excerpts are chosen for they are implied sounds captured in repeatability and recontextuality. The first part of the article offers an excerpt of the Bariolage from violin at bars (113-120) and its parallel piano transcription at bars (118-125). Significant expressions of registral change utilizing different voice parts (Soprano, Alto, Tenor) offer a wider expansion with piano. These excerpts were chosen after reviewing the original Bach Chaconne and its essentials in analytical aesthetics for the projection of beauty in symmetry-asymmetry-chaos in composition. This study captures the aesthetics of the beautiful from the original score of the violin Chaconne at (bars 89-96) and (bars 113-120) for Bach-Busoni piano transcription. Further, there are recommendations for future studies to explore vertical spaces and mathematical sequences embedded in the music in other sections. The findings of this study were implied through new music analytical formats to be applied in composition, pedagogy, and performance practice.

(Invited) Fluorescence Quenching Microscopy for Imaging 2D Materials: An Update

Fluorescence quenching microscopy (FQM) was initially developed for high throughput imaging of graphene based sheets on arbitrary substrates under a common fluorescence microscopy. It takes advantages of the long range, energy transfer-based fluorescence quenching effect of graphene-based materials, and can obtain images with high contrast and high layer resolution comparable to those of scanning electron microscopy (SEM) and atomic force microscopy (AFM). FQM was later applied to image other strongly quenching sheets such as transitional metal dichalcogenides.The high-contrast optical imaging of nearly transparent 2D materials such as clays and some oxides sheets has been an outstanding challenge; yet it is a critical research capability needed in the synthesis and processing of these materials, which have shown promise in a number of applications including barrier coatings, membranes, and composites. Using delaminated silicate clay and titania sheets as model system, here we show that these weakly quenching, nearly transparent 2D sheets can also be readily imaged by FQM based on a new mechanism with SEM and AFM level of contrast and layer resolutions. When different 2D materials are co-deposited, FQM not only differentiates them readily based on their quenching capabilities, but also can resolve their vertical stacking sequence based on the contrast of their overlapped areas.

Design and experimental research of test platform for characterizing a thermoelectric generator based on STM32

In order to solve the problem of low utilization rate of industrial low-grade thermal energy and actively implement the national policy of energy conservation and emission reduction, a low-temperature differential Thermoelectric generator device is designed and implemented based on the thermoelectric effect. According to the basic heat flow method of thermodynamics, the vertical installation sequence of the instrument is determined, and the simulated heat source is carried out in the laboratory. DJR-G type silicon rubber heater is used as the heating device, the fin radiator is used as the radiator and combined with the insulation layer to build the Thermoelectric generator test platform. STM32 microcontroller is the main control core of the instrument; tec1-12708t200 thermoelectric module is the power generation carrier; the main output characteristic parameters of the instrument are displayed on LCD in real time, and the change curve of the output parameters is monitored on the upper computer in real time. The experimental data show that when the load resistance is 2.5 Ω, it matches the equivalent resistance, and its output power reaches the maximum value; when the cold end of the Thermoelectric generator device is effectively cooled, its output power will increase by 0.1W. The conclusion shows that the instrument can effectively realize the Thermoelectric generator function and improve the utilization rate of low-grade thermal energy.

Macro- and microfeatures of Early Cambrian dolomitic microbialites from Tarim Basin, China

The fabrics of microbialites preserved in limestones are generally better than in dolostones. What are the fabrics of the microbialites preserved in heavily dolomitized dolostones? This paper presents an example of a strongly dolomitized Cambrian microbialite profile. The Xiaoerblak Formation (Cambrian Series 2 Stage 3 and lower Stage 4) of the Sugaitblak section in Aksu, Xinjiang Uygur Autonomous Region, China is mainly composed of microbial dolostones. Due to strong alteration by diagenesis, their features, formation and environments have not been fully understood. Here, based on detailed observation on outcrops and thin sections, we show that this formation comprises four kinds of microbialites: laminite, thrombolite, thrombolitic laminite, and Renalcis framestone, in five intervals (Interval I to Interval V). We identified three main types of microbialite fabrics, i.e., clotted fabric, laminated fabric and skeletal fabric, and established a high-resolution vertical evolution sequence of the microbialites. The clotted fabric and the laminated fabric were further divided into subtypes. We found that the original fabrics were mainly affected by dolomitization, recrystallization and dissolution, and the alteration degree of the microbialite fabric is stronger in the lower part of this formation. The laminated fabric has the strongest resistance to diagenesis, followed by the clotted fabric. Based on studies of different rock types and sedimentary structures, we concluded that the sedimentary environment of Xiaoerblak Formation consists of three settings: a) Intervals I to III formed in restricted tidal flat environments, b) Interval IV and the lower part of Interval V in restricted deep subtidal environments, and c) upper part of Interval V in shallowing-up open subtidal environments.

Diverse floodplain deposits of reworked loess in a monsoon climate (Hanzhong Basin, central China)

AbstractThis paper describes an assemblage of diverse floodplain facies of reworked loess (facies b, c) in a Middle Pleistocene monsoonal setting of the Hanzhong Basin, central China. The vertical and lateral sedimentary sequences show changing energy conditions. Apart from the highest energy in the channel facies (facies a), a relatively high energy floodplain environment (facies b) prevailed in waterlogged conditions, with small, laterally migrating (sub)channels. Facies b generally interfingers with aggrading horizontal sheets of overbank deposits in alluvial pools and swamps in a floodplain with much lower energy (facies c), in which phases of stability (soil formation) occasionally interrupted overbank deposition. Reworked loess forms the main part of the floodplain deposits. The paleosols are considered to have been formed under low hydrodynamic conditions in an interglacial environment. These interglacial conditions follow the commonly assumed glacial conditions of channel facies a. The sedimentary successions in the floodplain show a recurrent composition and cyclicity between wet and dry floodplain sedimentation terminated by stability with soil formation. The cyclic rhythm of stacked high- and low-energy floodplain sediments is attributed to varied intensity of different hydrodynamic flooding events that may have been due to changing monsoonal rainfall or simple intrinsic fluvial behavior.

Sedimentology, petrography, and reservoir quality of the Zarga and Ghazal formations in the Keyi oilfield, Muglad Basin, Sudan

The Zarga and Ghazal formations constitute important reservoirs across the Muglad Basin, Sudan. Nevertheless, the sedimentology and diagenesis of these reservoir intervals have hitherto received insignificant research attention. Detailed understanding of sedimentary facies and diagenesis could enhance geological and geophysical data for better exploration and production and minimize risks. In this study, subsurface reservoir cores representing the Zarga formation (1114.70–1118.50 m and 1118.50–1125.30 m), and the Ghazal formation (91,403.30–1406.83 m) were subjected to sedimentological (lithofacies and grain size), petrographic/mineralogic (thin section, XRD, SEM), and petrophysical (porosity and permeability) analyses to describe their reservoir quality, provenance, and depositional environments. Eight (8) different lithofacies, texturally characterized as moderately to well-sorted, and medium to coarse-grained, sub-feldspathic to feldspathic arenite were distinguished in the cored intervals. Mono-crystalline quartz (19.3–26.2%) predominated over polycrystalline quartz (2.6–13.8%), feldspar (6.6–10.3%), and mica (1.4–7.6%) being the most prominent constituent of the reservoir rocks. Provenance plot indicated the sediments were from a transitional continental provenance setting. The overall vertical sequence, composition, and internal sedimentary structures of the lithofacies suggest a fluvial-to-deltaic depositional environment for the Ghazal formation, while the Zarga formation indicated a dominant deltaic setting. Kaolinite occurs mainly as authigenic mineral, while carbonates quantitatively fluctuate with an insignificant amount of quartz overgrowths in most of the analyzed cores. Integration of XRD, SEM, and thin section analysis highlights that kaolinite, chlorite, illite, and smectite are present as authigenic minerals. Pore-destroying diagenetic processes (e.g. precipitation, cementation, and compaction etc.) generally prevailed over pore-enhancing processes (e.g. dissolution). Point-counted datasets indicate a better reservoir quality for the Ghazal formation (ɸ = 27.7% to 30.7%; K = 9.65 mD to 1196.71 mD) than the Zarga formation (17.9% to 24.5%; K = 1051.09 mD to 1090.45 mD).

Sequence Stratigraphy, Sedimentary Characteristics of Barrier Coastal Sedimentary System of the Benxi Formation (Gaoqiao Area, Ordos Basin) and Implications for Gas Exploration

Benxi Formation is an important abundant natural gas resource in Gaiqiao area. Therefore, to analyze the sequence and sedimentary characteristics of the Benxi Formation and to provide guidance for predicting the favorable gas reservoir distribution. In addition, after comprehensive use of core, thin section, drilling, and logging data, the sedimentary microfacies of Benxi formation were studied. The Benxi Formation in Gaoqiao area is concluded to be a barrier coastal sedimentary system, subdivided into eight sedimentary microfacies, namely, tidal delta, tidal channel, sand flat, mixed flat, mud flat, peat flat, barrier bar, and lagoon mud microfacies. Along with sequence framework and sedimentary microfacies characteristics, planar distribution characteristics of sedimentary microfacies and vertical sequence characteristics are also studied. It is concluded that i) From west to east, peat flat - mud flat - mixed flat - sand flat - lagoon mud - barrier bar have been developed in the study area ii) Four typical vertical sequences have been identified: MA1, MA2, MA1, MA4. The first three sequences have developed extensively and completely in the study area, while the last one generally has one or more microfacies missing; iii) The sedimentary system of the Benxi Formation in Gaoqiao area is mainly vulnerable to tectonism, sequence, and sea-level changes. The Second Member is the target gas-producing strata of the formation. Both barrier bar and sand flat microfacies have a good gas display. However, the barrier bar microfacies are the most favorable natural gas distribution zones with giant and premium gas reserves.

Biodiversity changes of the Ordovician trilobites in the middle Yangtze region of South China

The biodiversity changes of trilobites in the middle Yangtze region of South China in the Great Ordovician Biodiversification Event and the end-Ordovician mass extinction have been analysed. The Ordovician trilobites in this region originated in the early Tremadocian and radiated from the late Floian to the early Katian. Two peaks of diversity appeared in the late Dapingian to the early Darriwilian and the early Katian. The extinction occurred in the late Katian, followed by a survival period in the Hirnantian. The Whiterock fauna began to surpass the Ibex fauna during the early Katian and were dominant by the late Katian to the Hirnantian, indicating that Cambrian Evolutionary Fauna was gradually replaced. The study once again confirms the view that the effects of factors such as sea level, climate, oxygen content, nutrient supply, and tectogenesis differ temporally and to different degrees in different regions, resulting in differences in the vertical sequence and horizontal combination of ecosystems, which is the reason for the different evolution patterns of Ordovician trilobites in different regions.

Estimating the population mean for a vertical profile of energy dissipation rate

Energy dissipation rates are an important characteristic of turbulence; however, their magnitude in observational profiles can be incorrectly determined owing to their irregular appearance during vertical evolution. By analysing the data obtained from oceanic turbulence measurements, we demonstrate that the vertical sequences of energy dissipation rates exhibit a scaling property. Utilising this property, we propose a method to estimate the population mean for a profile. For scaling in the observed profiles, we demonstrate that our data exhibit a statistical property consistent with that exhibited by the universal multifractal model. Meanwhile, the population mean and its uncertainty can be estimated by inverting the probability distribution obtained by Monte Carlo simulations of a cascade model; to this end, observational constraints from several moments are imposed over each vertical sequence. This approach enables us to determine, to some extent, whether a profile shows an occasionally large mean or whether the population mean itself is large. Thus, it will contribute to the refinement of the regional estimation of the ocean energy budget, where only a small amount of turbulence observation data is available.

Evolution of Ordovician cephalopod diversity in the Middle Yangtze region of South China and its controlling factors

The evolution of Ordovician cephalopod diversity in the Middle Yangtze region of South China has been analysed. The cephalopods in this region appeared in the earliest Tremadocian, radiated in the Early–Middle Floian and Middle Ordovician, and went through an extinction period during the Late Katian and Hirnantian. The composition of the cephalopod fauna underwent major changes in the Late Floian. Specifically, all the genera occurring in previous time periods disappeared and Tarphyceratida, Actinoceratida, and Orthoceratida appeared and prospered. Differences in the evolution of cephalopod diversity between Middle Yangtze region and other regions were detected, which were caused by differences in the vertical sequence and horizontal combination of controlling factors. Changes in living environments and the distribution of food resources prompted Ordovician cephalopods to evolve adaptations for life in deep-water environments. The low-temperature ocean current near the western coastline of Gondwana created favourable conditions for the Floian peak of cephalopod diversity in South China. The tectonic movements, high rainfall, and relatively closed environment of the Middle Yangtze region led to rapid sea level rise and hindered cephalopod diversification. These processes explain the low cephalopod diversity in the Late Ordovician and the absence of the previously reported Katian radiation peak in this region.