bluuebunny/crossref_metadata_2025 huggingface dataset:
Graphene oxide-grafted plasmonic Au@Ag nanoalloys with improved synergistic effects for promoting hot carrier-driven photocatalysis under visible light irradiation
Authors: Li Shuang , Zhao Jinhua , Liu Guiyuan , Xu Linlin , Tian Yue , Jiao Anxin , Chen Ming
Published: December 2020

Plasmonic metallic nanostructure with unique hot carrier-driven photocatalysis has recently emerged as a promising photocatalyst. Herein, we show that the plasmonic photocatalysis can be significantly promoted by supporting bimetallic Au@Ag nanoalloys (NAs) on graphene oxide (GO). The obtained Au3@Ag1/GO (molar ratio of Au to Ag∼3:1) with improved synergistic effects provides a remarkable higher visible-light (>400 nm) photocatalytic activity for a complete degradation (99.36%) of tetracycline hydrochloride (TCH) molecules within 70 min, while about 61.74% or 62.38% via monometallic Au/GO or Ag/GO. The optimum photocatalytic performance is attributed to the production of high yield hot carriers on NAs with enhanced localized surface plasmon resonance property and the pronounced photoinduced electron-transfer ability of modified GO support by overgrowth of NAs. These findings enable the optimal Au3@Ag1/GO to become an appealing high-performance photocatalyst for promoting diverse photochemical reactions.
Influences of heating and plasma density on impurity production and transport during the ramp-down phase of JET ILW discharge
Authors: Ivanova-Stanik I , Zagórski R , Chomiczewska A , Lomas P J , Voitsekhovitch I , Ferreira D R , Sozzi C , Joffrin E , Lerche E
Published: December 2020

The aim of this paper is to study the influences of plasma heating and plasma density on impurity production and transport during the plasma-termination phase. We have analyzed the ramp-down (RD) phase of a set of representative high-current JET ITER-like wall discharges: #92 437 (disrupted) and #92 442 (soft landing), characterized by a high plasma current of I

p
= 3.5MA. Analysis is performed for different time slots within the RD phase, corresponding to different levels of electron line density and auxiliary heating power. Since the deuterium gas fluxes are different, the influence of the separatrix density is also analyzed. The main conclusion from the simulations is the observation that for the same average-electron density, a decrease of the separatrix density leads to an increase of the plasma temperature at the divertor plate, leading to increased W production and consequently to a larger W concentration and radiation in the core. When the central electron temperature approaches the 2 keV level, corresponding to the maximum W and Ni cooling rate, the radiation in the plasma’s center is enhanced. Ni radiation is more important in the RD phase.
Multiphase lattice metamaterials with enhanced mechanical performance
Authors: Usta Fatih , Scarpa Fabrizio , Türkmen Halit S , Johnson Peter , Perriman Adam W , Chen Yanyu
Published: December 2020

We describe here the quasi-static crushing behavior of novel classes of multiphase (hybrid) hierarchical lattice metamaterials. The first class is represented by a hybrid architecture combining a hierarchical honeycomb with polyurethane foam filler, while the second is a multiphase structure produced by injecting an alginate hydrogel into the hierarchical voids of the honeycomb metamaterial. Twelve different auxetic (i.e. negative Poisson’s ratio) and non-auxetic metamaterial architectures have been 3D printed and subjected to edgewise compression crushing loading. A parametric numerical analysis has been also performed using validated finite element models to identify best metamaterial architecture configurations. Configurations filled with the hydrogel showed a significant stabilization of the deformation mechanism during large deformation edgewise compression. The use of metamaterials designs with internal slots and round in the ribs also filled by polyurethane rigid semi-reticulated foam feature however significant increases in terms of specific stiffness, mean crushing force, strength and energy absorption. The enhancement is particularly evident for the hybrid lattice metamaterials auxetic configurations.
Mechanical property and deformation mechanism of gold nanowire with non-uniform distribution of twinned boundaries: A molecular dynamics simulation study*
Authors: Xiao Qi-Xin , Hou Zhao-Yang , Li Chang , Niu Yuan
Published: December 2020

The mechanical property and deformation mechanism of twinned gold nanowire with non-uniform distribution of twinned boundaries (TBs) are studied by the molecular dynamics (MD) method. It is found that the twin boundary spacing (TBS) has a great effect on the strength and plasticity of the nanowires with uniform distribution of TBs. And the strength enhances with the decrease of TBS, while its plasticity declines. For the nanowires with non-uniform distribution of TBs, the differences in distribution among different TBSs have little effect on the Young’s modulus or strength, and the compromise in strength appears. But the differences have a remarkable effect on the plasticity of twinned gold nanowire. The twinned gold nanowire with higher local symmetry ratio has better plasticity. The initial dislocations always form in the largest TBS and the fracture always appears at or near the twin boundaries adjacent to the smallest TBS. Some simulation results are consistent with the experimental results.
Effect of Sm doping into CuInTe2 on cohesive energy before and after light absorption
Authors: Wang Tai , Guo Yong-Quan , Wang Cong
Published: December 2020

The effects of Sm doping into CuInTe2 chalcopyrite on the cohesive energy before and after light absorption are systematically investigated by the empirical electron theory (EET) of solids and molecules. The results show that the static energy of CuIn1 – x
Sm
x
Te2 decreases with Sm content increasing due to the valence electronic structure modulated by doping Sm into CuIn1 – x
Sm
x
Te2. The calculated optical absorption transition energy from the static state to the excited energy level in CuIn1 – x
Sm
x
Te2 accords well with the experimental absorption bandgap of CuIn1 – x
Sm
x
Te2. Moreover, it is found that the energy bandgap of CuIn1 – x
Sm
x
Te2 is significantly widened with Sm content increasing due to its special valent electron structure, which is favorable for enhancing the light absorption in a wider range and also for the potential applications in solar cells.
Speech-imagery-based brain–computer interface system using ear-EEG
Authors: Kaongoen Netiwit , Choi Jaehoon , Jo Sungho
Published: December 2020

Objective. This study investigates the efficacy of electroencephalography (EEG) centered around the user’s ears (ear-EEG) for a speech-imagery-based brain–computer interface (BCI) system. Approach. A wearable ear-EEG acquisition tool was developed and its performance was directly compared to that of a conventional 32-channel scalp-EEG setup in a multi-class speech imagery classification task. Riemannian tangent space projections of EEG covariance matrices were used as input features to a multi-layer extreme learning machine classifier. Ten subjects participated in an experiment consisting of six sessions spanning three days. The experiment involves imagining four speech commands (‘Left,’ ‘Right,’ ‘Forward,’ and ‘Go back’) and staying in a rest condition. Main results. The classification accuracy of our system is significantly above the chance level (20%). The classification result averaged across all ten subjects is 38.2% and 43.1% with a maximum (max) of 43.8% and 55.0% for ear-EEG and scalp-EEG, respectively. According to an analysis of variance, seven out of ten subjects show no significant difference between the performance of ear-EEG and scalp-EEG. Significance. To our knowledge, this is the first study that investigates the performance of ear-EEG in a speech-imagery-based BCI. The results indicate that ear-EEG has great potential as an alternative to the scalp-EEG acquisition method for speech-imagery monitoring. We believe that the merits and feasibility of both speech imagery and ear-EEG acquisition in the proposed system will accelerate the development of the BCI system for daily-life use.
Adequately reflecting the severity of tropical cyclones using the new Tropical Cyclone Severity Scale
Authors: Bloemendaal Nadia , de Moel Hans , Mol Jantsje M , Bosma Priscilla R M , Polen Amy N , Collins Jennifer M
Published: December 2020

For decades, meteorologists and governments have been warning communities in coastal areas for an imminent tropical cyclone (TC) using the Saffir-Simpson Hurricane Wind Scale (SSHWS). The SSHWS categorizes a TC based on its maximum wind speed, and is used in defining evacuation strategies and humanitarian response. However, the SSHWS considers only the wind hazard of a TC, whereas a TC can also cause severe conditions through its high storm surges and extreme rainfall, triggering coastal and inland flooding. Consequently, the SSHWS fails to mirror the TC’s total severity. This becomes evident when looking at past events such as Hurricane Harvey (2017), which was classified as a Tropical Storm while it caused widespread flooding in the Houston (TX) area, with precipitation totals exceeding 1.5 m. Without including storm surge and rainfall information, adequate risk communication with the SSHWS can be challenging, as the public can (mistakenly) perceive a low-category TC as a low-risk TC. To overcome this, we propose the new Tropical Cyclone Severity Scale (TCSS) that includes all three major TC hazards in its classification. The new scale preserves the categorization as used in the SSHWS, to maintain familiarity amongst the general public. In addition, we extend the scale with a Category 6, to support communication about the most extreme TCs with multiple hazards. The TCSS is designed to be applied on a local-scale, hereby supporting local-scale risk communication efforts and evacuation strategies prior to a TC landfall. The scale can be used for risk communication on both the total TC risk and on the categories of the separate hazards, which can be valuable especially in cases when one hazard is the predominant risk factor, such as excess rainfall triggering flooding.
Reply to comment on ‘The relativistic Aharonov–Bohm–Coulomb system with position-dependent mass’
Authors: Oliveira R R S , Filho A A Araújo , Maluf R V , Almeida C A S
Published: December 2020

It is shown that the results of our paper are correct, although the use of the chirality operator γ
5 = σ
1 in the paper is not correct, as fairly the authors of the comment stated.
Phase space theory for open quantum systems with local and collective dissipative processes
Authors: Merkel Konrad , Link Valentin , Luoma Kimmo , Strunz Walter T
Published: December 2020

In this article we investigate driven dissipative quantum dynamics of an ensemble of two-level systems given by a Markovian master equation with collective and local dissipators. Exploiting the permutation symmetry in our model, we employ a phase space approach for the solution of this equation in terms of a diagonal representation with respect to certain generalized spin coherent states. Remarkably, this allows to interpolate between mean field theory and finite system size in a formalism independent of Hilbert-space dimension. Moreover, in certain parameter regimes, the evolution equation for the corresponding quasiprobability distribution resembles a Fokker–Planck equation, which can be efficiently solved by stochastic calculus. Then, the dynamics can be seen as classical in the sense that no entanglement between the two-level systems is generated. Our results expose, utilize and promote techniques pioneered in the context of laser theory, which can be powerful tools to investigate problems of current theoretical and experimental interest.
Carbonate fine lithology prediction using amplitude attribute of PS-wave
Authors: Qiyan Chen , Hongqiu Wang , Jianhu Gao , Xin Guo
Published: December 2020

The Lower Permian Maokou Formation and Qixia Formation in central part of Sichuan Basin have huge natural gas exploration potential. For the Maokou Formation, there is argillaceous limestone in the limestone background, and thin dolomite reservoirs are developed. The ability to use conventional PP-wave data to predict lithology and dolomite reservoirs is insufficient. In PP-wave seismic section, the response of argillaceous limestone and dolomite in the limestone background is not obvious, which limits the prediction accuracy of lithology. Making full use of high-precision matched PP-wave and PS-wave seismic data, we find a special phenomenon in the Maokou Formation that PP-wave usually shows weak amplitude and poor continuity while PS-wave shows stronger amplitude and better continuity. Aimed at the particular phenomenon, through multi-wave seismic forward modelling, log lithology interpretation, cross plot of P-impedance with S-impedance and seismic section comparison of PP-wave and PS-wave, it is clear that the weak peak of PP-wave and strong peak of PS-wave reflects weak and subtle change in lithology, which shows the existence of argillaceous limestone in limestone background. And the gas-bearing dolomite reservoirs are characterized by low frequency and weak amplitude on PP-wave, while show weak peak feature on PS-wave. Compared with PP-wave, the favorable lithology (dolomite) distribution predicted by maximum peak amplitude of PS-wave is more consistent with reservoir distribution and origin of hydrothermal-karst-controlled dolomite. Result of lithology prediction by PS-wave is reasonable and reliable for Maokou Formation.
Geochemical characteristics and genesis of the Upper Paleozoic natural gas in Longdong area, Ordos Basin, NW China
Authors: Kong Qingfen , Kong Lingyin , Li Jianfeng
Published: December 2020

The Upper Paleozoic gases from the Longdong areas in the Ordos Basin are characterized by low contents of heavy hydrocarbon gases, the mean value of wetness as 2%, relatively heavy δ13C1(δ13C1 value -28.3‰), and large variations in δ13C2
+. The distribution pattern of carbon isotopic sequence of natural gas is mainly characterized by the abnormal light δ13C2
+ values and carbon isotopic reversal. According to the organic geochemical characteristics of natural gas and the development of gas-source rocks, the upper Paleozoic natural gas in Longdong area belongs to high mature and over-mature “coal-formed gas”. In theory, only the mixture of highly mature gas with extremely low contents of heavy hydrocarbon gases and a small amount of natural gas with higher contents and lighter carbon isotopic composition of heavy hydrocarbon gases can lead to the occurrence of abnormally light δ13C2
+ and the carbon isotope reversal between methane and ethane. The mixed gas is probably derived from the thermal cracking of a small amount of residual soluble organic matter in the gas-source rocks and reservoirs during the initial stage of the uplift movement at the end of Early Cretaceous. Key words: Ethane carbon isotope; Inverted sequence of carbon isotopic composition; Natural gas of high maturity; natural gas genesis; Ordos Basin.
Shale gas prospect of different source rock types from Early Maastrichtian Mamu Formation, Anambra Basin, Nigeria
Authors: Faboya O L , Sonibare O O , Abimbade S F , Liao Z W
Published: December 2020

The gas prospect of three identified source rock types from the Early Maastrichtian Mamu Formation of the Anambra Basin, Nigeria was evaluated by thermal simulation, followed by gas composition analyses of the generated hydrocarbons. The amounts of C1 and ΣC1-5 generated at the highest examined pyrolysis temperature of 480°C (Easy Ro of 3.27%) range from 3.52 to 32.00 ml/g rock and 4.08 to 43.44 ml/g rock, respectively. The sub-bituminous coal has the highest gaseous hydrocarbon generative potential up to late gas generation stage, followed by carbonaceous shale while shale has the least productive capacity. The recovery of gaseous hydrocarbons may be influenced by the ratio of TOC to clay content in all the source rocks. The gas dryness index indicates that the shale is the driest among the source rock types.
Study on gas yields and generation kinetics of a type I kerogen sample by open and confined pyrolysis
Authors: Liu Jinzhong , Weng Cui , Li Yong , Yang Xiao
Published: December 2020

A shale sample collected from the Neoproterozoic Xiamaling Formation in Xiahuayuan region, North China, was studied by a newly developed apparatus, Multiple-Gas Container Open Pyrolysis Devise, and data were compared with those from confined gold tube pyrolysis. This device is mainly composed by a pyrolysis heater and 15 gas containers, a whole heating process was divided into 15 time/temperature segments, gases generated in different temperature segments with carrier gas were temporarily conserved in their gas container correspondingly. When pyrolysis completed, gases in each container were introduced to a gas chromatography for analysis. Sample was heated from room temperature to 650 °C. Because oil generated from sample was removed by carrier gas immediately from heating area, oil cracking did not play an important role in gas generation. Maximum yield of methane is only 28.4% of that from confined gold tube pyrolysis. Trend of methane yield from open method is similar to that from confined method in EASY%Ro range from 0.58% to 1.80%, indicating that oil cracking in this maturity range is minor, but at higher temperature, gas yields produced in confined pyrolysis increased rapidly, much higher than those from closed method. Activation energies of methane generation from open method ranges from 53 to 72 kcal/mol, central value of C1, C2, C3 decline with their carbon number, showing a clear generating order that the gas with larger carbon number will be generated earlier. δ 13C of methane from open method is similar to that from confined method in EASY%Ro range from 0.58% to 2.2%; But in later pyrolysis stage, it is much heavier than that from confined method. δ 13C deviation of methane between open and confined methods provides a possible way to calculate proportion of the gas from oil cracking. This open pyrolysis device offers a convenient and efficient way to simulate gas generation potential and acquire kinetics parameters, especially for the source rock from open or semi open gas producing strata.
Gas generation evaluation of Pingliang shale in Weibei Uplift, Ordos Basin using PetroMod
Authors: Shi Shuyong , Liao Lingling , He Zhihua , Wang Yunpeng
Published: December 2020

Ordos Basin is an important large petroliferous basin in China. In order to recover gas generation history and evaluate gas resources of Pingliang shale in Weibei Uplift, Ordos Basin, we took the Pingliang shale of Well XT-1 as the research target. We reconstructed burial and thermal histories of Pingliang shale based on PetroMod software. Besides, we also recovered gas generation history and its resources potential. The modeling results show that Well XT-1 had experienced five major tectonic stages. The burial depth of the bottom of Pingliang shale reached the maximum with the value of approximately 4500 m at the late Cretaceous and the current burial depth is 3068 m. The results of thermal history show that Pingliang shale had experienced oil-generation and gas-generation stages and current Ro is 2.52%. Based on the calculation results about gas generation history, generation masses of methane, wet gas, and total gas are 1.24 × 108 kg/km2, 0.88 × 108 kg/km2, 2.12 × 108 kg/km2, respectively, which shows great gas resource potential of Pingliang shale in Weibei uplift, Ordos Basin.
Sedimentary geochemical records and their depositional environmental significance during Cambrian-Ordovician transition in well YD 2, eastern Tarim Basin, NW China
Authors: Wang H Z , Zhang H Z , Deng Q , Wei Z W , Li S D , Cheng B , Liao Z W
Published: December 2020

In the eastern part of Tarim Basin, thick carbonate rocks were developed in the Upper Cambrian, while thick grey-black mudstone in the Lower Ordovician. Due to the complex tectonic and geological conditions in the basin, there are still many uncertainties in the study of the sedimentary environment, post-diagenesis and hydrocarbon accumulation conditions during the Cambrian-Ordovician transition. In this paper, 24 drilling core samples of the key strata of the Upper Cambrian-Lower Ordovician in the well YD2 were selected as the main research objects. Their mineral composition, major and trace elements (including REE) were analyzed. The results showed that the proportion of carbonate-siliciclastic sources in the rocks was controlled by the sedimentary environment, especially seawater depth. The oxic-suboxic sedimentary environment is indicated by the redox-sensitive elements and other trace elements (especially REE). This is consistent with the mineralogical features of the samples and the relatively low TOC. The elements Mn, Cr, V, Ni, on the whole, show a trend of first increasing, then decreasing, and repeated occurrence, indicating the sea level fluctuation cycle. In addition, according to the Ba/Sr and Mn/Sr ratios, the upper Cambrian carbonate rocks were normal marine sediments with weak post-diagenesis. Quartz, dolomite and calcite veins filling the fissures of the samples may have formed in the stage of intense uplift denudation, which was unfavourable to the formation of large oil and gas reservoirs.
Gas detecting of the Lower Permian dolomite reservoirs in Sichuan Basin using amplitude ratio attribute of PP-wave to PS-wave
Authors: Hongqiu Wang , Lu Zhou , Qiyan Chen , Kang Chen , Ronghua Wang , Xin Guo
Published: December 2020

At present, multi-wave multi-component seismic exploration has a good effect in the gas-bearing structural imaging improvement, fracture detection, clastic rock lithology description, reservoir monitoring, etc., but in gas detection, especially for the deep carbonate reservoir, there are not many successful cases. The paper takes the 5000m deep Lower Permian Qixia Formation dolomite gas reservoir in the central part of Sichuan Basin as the research target. Aiming at the differences in gas production characteristics of different wells and difficulty in gas detection, based on the high-precision matched 3D multi-wave seismic data by seismic processing and fine horizon interpretation of target formation, the differences between the PP- and PS-wave reflection amplitudes of high-production wells, low-production wells and poor gas wells are compared and analyzed, and multi-wave forward modelling and analysis are carried out. It is clear that the high production gas layer has the characteristics of strong PP-wave reflection and weaker PS-wave reflection. With the gas production decreasing from high to low, the reflection amplitude of PP gradually weakens, while that of PS change little and nearly have no obvious abnormalities. Finally, attribute of amplitude ratio of PP to PS were extracted for gas detection, which is in good agreement with the gas characteristics of the known wells and consistent with current geological understanding. The amplitude ratio attribute of PP to PS could provide a quick and reliable gas detection method for the deep dolomite reservoir.
Hydrocarbon generation from bacterial biomass in ca. 1320 million years ago
Authors: Wang Huajian , Zhang Shuichang , Wang Xiaomei , Zhang Baomin , Bian Lizeng , Bi Lina
Published: December 2020

Bacteria are the oldest life on the Earth. Some of them, such as cyanobacteria, can produce oxygen and organic matter through photosynthesis. However, the hydrocarbon generation ability of these bacterial biomass is still unclear. Here we reported the molecular evidence from the wrapped bitumen in well-preserved silicified concretions from the Xiamaling Formation, North China. The absence of steranes indicated negligible contribution of eukaryotic algae to the bitumen. Abundant hopanes, 13α(n-alkyl)-tricyclic terpanes and other biomarkers of bacteria prove that bacterial biogenic organic matter can generate hydrocarbons on a large scale. Combined with our previous microfossils and elements studies, these bitumen were considered to be from the Xiamaling shales, for the intrusion of Yanliao large igneous provinces into the organic-rich Xiamaling shales at ca. 1320 million years ago.
Geochemical characteristics and significance of the bitumen in Sinian reservoirs in Sichuan basin and its periphery
Authors: Xie Z Y , Li J , Zhang L , Yang C L , Guo J Y , Wang Z H , Li Z S , Guo Z Q , Zhang G W , Li J , Hao A S
Published: December 2020

The bitumen of Doushantuo Formation distributed along fractures has been firstly discovered in the dolomite reservoirs of Dou-3 Member in Zigui region, Yichang, Hubei. Research has been conducted using multiple methods on the characteristics of the newly discovered bitumen of Doushantuo Formation, bitumen of Dengying Formation-Longwangmiao Formation in Anyue gas field in Sichuan Basin, and bitumen of Sinian and source rocks of Sinian-Cambrian in Northeast Sichuan. The results show:①The reflectivity of the bitumen of Dou-3 Member is about 2.8%; ② The carbon number of n-alkanes in the bitumen of Dou-3 Member is C13-C33, where nC17 is the main peak; the relative proportion of the regular steranes is C27≈C29>C28, and C27, C28 and C29ααα20R steranes are distributed in “L” shape; abundant tricyclic terpanes and pentacyclic triterpanes have been detected, and the abundance of gammacerane is high; Aromatics are mainly phenanthrene series compounds. ③ The heteroatomic compounds in the bitumen of Dou-3 Member are mainly O2 carboxylic acids, and the oxygen compounds in the bitumen of Dengying Formation in Anyue gas field are close to those of the source rocks of Doushantuo Formation. The research results are of vital guiding significance to the study of potential source rocks of Doushantuo Formation in Sichuan Basin and the exploration of oil and gas from the source rocks of Doushantuo Formation.
Chemical characteristics of Middle Permian formation water and hydrocarbon preservation conditions in Northwest Sichuan
Authors: Yang C L , Xie Z Y , Pei S Q , Guo J Y , Zhang L , Dong C Y , Hao A S , Yang C X , Liu Z X
Published: December 2020

The analysis of the chemical characteristics of the Middle Permian formation water in 10 wells in the northwest of Sichuan Basin indicates that: the TDS of the Middle Permian formation water in Northwest Sichuan increases longitudinally with the burial depth of the formation, and the formation water is mainly of CaCl2 type (Surin classification), Cl-Na-Ca type and Cl-Ca-Na type (Shukarev classification). The rNa+/rCl− and rSO4
2-*100/rCl− of the formation water are 0.05-0.95 and 0-5 respectively, reflecting strong water-rock interaction and strong sealing conditions. The analysis of the chemical characteristics of formation water and the preservation conditions of oil and gas shows that the overall preservation conditions of the Middle Permian in Northwest Sichuan are good, most of which is located in the “preservation zone”; longitudinally, the preservation conditions of Qixia Formation are better than those of Maokou Formation; areally, the preservation conditions of Shuangyushi and Jiulongshan regions are good; the sealing property of the strata in Hewanchang region is poor.
Geochemical studies on high-efficiency hydrocarbon expulsion of Triassic lacustrine shale in the Ordos Basin, China: implications for tight and shale oil accumulation
Authors: Yang Weiwei , Zhang Wenzheng , Li Shixiang , Li Shanpeng
Published: December 2020

The organic-rich sediments developed at the bottom of Chang7 Member of the Upper Triassic Yanchang formation, which can be divided into oil shale and black mudstones, are dominate source rocks for low permeability and tight oil reservoirs in Mesozoic petroleum system of Ordos Basin. The hydrocarbon expulsion characteristics of the organic-rich sediments have been investigated by geology and geochemistry data. By comparison with the geochemical parameters of crude oil samples and mudstone extracts, Chang7 shale has many geochemical evidences on high rates of hydrocarbon expulsion. Lower conversion rate of chloroform extracted bitumen “A”, especially for the samples with TOC higher than 10%; lower productivity indexes and lower hydrogen indexes reducing with TOC increasing; lower ratios of saturates/aromatics but higher contents of polar components for residual bitumen “A”; heavier stable carbon isotopes of residual hydrocarbons. It should be noted that the source rock evaluation and oil-source correlation would be misunderstood based on these abnormal geochemical data caused by high-efficiency hydrocarbon expulsion. Calculation for rock samples have shown that the expelled rates of the shale samples averaging 70% are significantly higher than those of the mudstone samples. Chang 7 shale with large amounts of hydrocarbons generated and expelled is critical for hydrocarbon accumulation in low-permeability and tight oil reservoirs. Also, Chang7 organic-rich rocks is an important exploration field of shale oil in the future.
Geochemistry of light petroleum from the North of Dongying Depression
Authors: Zhai Zheng , Wang Xuejun , Cao Zhongxiang , Qi Yanli , Bao Yan
Published: December 2020

With ever-increasing exploration for oils, exploration has inevitably extended into deep layers. Considerable quantity of light oil is discovered from deep Es4
lower layer in the northern steep slope zone of Dongying Depression, Bohai Bay Basin. The oils are characterized by high content of saturated hydrocarbon and low concentration of biomarker and sulphur content. Eleven oil samples and forty-five source rock samples are finely analysed. According to the results of monomer hydrocarbon isotope analysis, carbon and oxygen isotope composition analysis and light hydrocarbon analysis, it is confirmed that the oils in deep strata of northern steep slope zone reach high mature lever. The light oils in the northern steep slope zone have a relationship with deep Es4
lower hydrocarbon source rocks by the results of monomer hydrocarbon isotope and light hydrocarbon analysis. Thermal evolution studies show the top Es4
lower hydrocarbon source rocks have a high thermal evolution level. The top Es4
lower hydrocarbon source rocks have relatively high organic abundance and are dominated by types I-II1 kerogen. This research is helpful for unravelling deep petroleum resources evaluation in this area. The viewpoint will be of great significance in future exploration. Moreover, the views in this paper can also be applied to other basins to explore for deep oil reservoirs.
Control of thermal evolution of source rocks on hydrocarbon distribution in Kuqa foreland basin, Tarim Basin, NW China
Authors: Zhang Haizu , Zhao Qing , Su Zhaohong , Lu Yuhong , Zhang Ke
Published: December 2020

Kuqa foreland basin is the foreland basin with the highest degree of oil and gas exploration and research in China. On the basis of deep understanding of hydrocarbon accumulation conditions and accumulation process in Kuqa foreland basin, the oil and gas distribution law of Kuqa foreland basin is summarized: (1) In the KS2-KS5 well block in the center of the basin, the maturity of source rock Ro is more than 2%, and the maximum is more than 3.5%, High over mature dry gas reservoirs are mainly formed in these area. (2) In Bozi-Dabei area at the west end of the basin and Dina-Yinan areas in the east end, the maturity Ro of source rocks mainly ranges from 1.2% to 2.0%, mainly forming condensate gas reservoirs with low condensate oil content. (3) In the northern structural belt and southern slope belt of the periphery of the basin, far away from the mature center of the source rock, the maturity of the source rock is relatively low and Ro is between 0.6% and 1.2%, which mainly forms oil and gas reservoirs and condensate reservoirs with high condensate oil content. From east to west, there are differences in structural characteristics, reservoir types, reservoir forming characteristics and resource potential of different structural sections, which are characterized by oil and gas enrichment in the middle section. The distribution and phase difference of oil and gas in Kuqa foreland basin are mainly controlled by the maturity of source rocks and the process of hydrocarbon accumulation. Through the understanding of hydrocarbon accumulation law and oil-gas distribution characteristics, it is of certain guiding significance to determine the next step exploration direction of Kuqa foreland basin.
Hydrocarbon generation potential of coal measure source rocks from lower Permian Shanxi Formation in the central-eastern Ordos Basin, China: control from sedimentary facies
Authors: Zhao Weibo , Zhang Hui , Liu Min , Zhang Tao , Wang Yunpeng , Guo Huijuan
Published: December 2020

Source rocks of Shanxi Formation widely distributed in the Ordos Basin were deposited in different sedimentary facies. Different sedimentary facies differ in sedimentary environment and could have great impact on the accumulation of organic matters. TOC content and S1+S2 values of shale and coal samples from different sedimentary sub-facies of Shan 1 and Shan 2 sections of Shanxi Formation were measured to investigate the influence of sedimentary facies on organic geochemistry characteristics. The results showed that the average TOC content of shale samples from the pro-delta sub-facies of Shan 1 section was higher than other sub-facies and the shale samples from the shore shallow lake sub-facies of Shan 2 section had higher TOC content when compared with other three sub-facies. Compared with Shan 1 section, the Shan 2 section was richer in organic matter. And the hydrocarbon generation potential of source rocks from Shan 2 section was better than that of Shan 1 section. More than 50% of shale samples from the Shan 2 section was of fair to good hydrocarbon generation potential. This study could provide a framework for the identification of potential areas for conventional and unconventional petroleum exploration.
The impact of heat input on the microstructures, fatigue behaviors, and stress lives of TIG-welded 6061-T6 alloy joints
Authors: Rojas Hugo , Molina Arturo , Valdez Socorro , Campillo Bernardo , Martínez Horacio , Sedano Alejandro , Serna Sergio
Published: December 2020

This work shows that heat input is an important parameter that influences microstructural changes in the heat-affected zones (HAZs) of TIG-welded 6061-T6 alloy joints and their fatigue behavior. Double-shielded TIG samples were welded using various heat input parameters and a gas mixture of 50% He and 50% Ar was used to produce an improved weld penetration, their mechanical properties and microstructures of the samples were compared to those of the unwelded alloy. The mechanical properties of the aluminum alloys and the welding zones were evaluated by performing tensile and fatigue tests. The fatigue behaviors of the 6061-T6 joints welded with different heat inputs were assessed by performing cyclic fatigue experiments. Their microstructures were examined via optical microscopy and scanning electron microscopy (SEM). Grain coarsening was observed in the fusion zones (FZs), and heat input during TIG welding made the HAZs larger. Applying the lowest heat input value yielded samples with poor ultimate tensile strength, which was attributed to partial penetration and the presence of pores in the welded joints. The oxygen content of the weld pool depended directly on the shielding method and the surface temperature distribution.
Effect of doping and pressure on the electronic and magnetic properties of the quaternary Heusler alloys
Authors: Estaji Nasrin , Afshar Mahdi
Published: December 2020

The effect of doping on the electronic structures and magnetic properties of the quaternary Heusler alloys under pressures is investigated. Electronic structure calculations reveal that ZrCoTiSi is a half-metallic ferromagnet with a total magnetic moment of 3.00 μ
B, which mostly arises from the 3d electrons of Ti atoms. In order to investigate the doping effects, different proportions of Y, Fe, Sc and Al atoms are substituted for Zr, Co, Ti and Si atoms, respectively. The calculated results on the basis of the density functional theory (DFT) indicate that, except Sc doping for x > 0.50, other substituted alloys can succeed the widely known Slater–Pauling rule (Mt = Zt − 18) of the ideal half-metallic materials, and preserve their half-metallic properties with full spin polarization. In addition, the behaviors of alloys with different concentrations of x under various pressures are investigated. ZrCoTi[Si(1 − x)Al(x)] and [Zr(1 − x)Y(x)]CoTiSi alloys keep up their half-metallicity by increasing proportions of x doping (0 ≤ x ≤ 1) under higher pressure in the range of 3.01 GPa to 17.61 GPa for Al doping and 3.01 GPa to 14.11 GPa for Y doping. However, in the replacement of Fe for Co in Zr[Co(1−x)Fe(x)]TiSi alloys, the resistance against pressure to conserve half-metallicity decreases from 3.01 GPa to 2.05 GPa. The Sc doping in ZrCo[Ti(1−x)Sc(x)]Si alloys causes loss of half-metallicity for x > 0.50, and endures up to 1.67 GPa external pressure to preserve their half-metallic properties.
Effect of sintering temperature on microstructure and properties of nano-WC particle reinforced copper matrix composites prepared by hot-pressing sintering
Authors: Zhou Weiwei , Hong Lekang , Wang Yingjun , Ye Nan , Tang Jiancheng
Published: December 2020

A novel nano-WC/Cu-based composite with nanometer WC dispersed in the copper matrix was successfully prepared by vacuum hot-pressing sintering. The effects of different hot-pressing sintering temperatures on the microstructure, conductivity, strength, and hardness of the composite were investigated. As a result, with the increase of temperature, the distribution of nano-WC particles in the matrix is more even, and the relative density can reach about 100% when sintering temperature increase to 1075 °C. The electrical conductivity of the composites sharply increases from 62.5 to 90%IACS when sintering temperature increase from 950 °C to 1100 °C. Furthermore, as the sintering temperature rises from 950 °C to 1100 °C, the ultimate tensile strength gradually increases from 123 to 425 Mpa, and the hardness increases from 127.5 to 150 HV. In addition, the composite also displayed excellent resistance to high temperature softening at 800 °C.
The Biology of the Cape Honey Bee,Apis mellifera capensis(Hymenoptera: Apidae): A Review of Thelytoky and Its Influence on Social Parasitism and Worker Reproduction
Authors: Mumoki Fiona N , Yusuf Abdullahi A , Pirk Christian W W , Crewe Robin M
Published: December 2020

Cohesion in social insect colonies is maintained by use of chemical signals produced by the queen, workers, and brood. In honey bees in particular, signals from the queen and brood are crucial for the regulation of reproductive division of labor, ensuring that the only reproductive female individual in the colony is the queen, whereas the workers remain reproductively sterile. However, even given this strict level of control, workers can, in principle, activate their ovaries and lay eggs. Although much is known about the behavioral and physiological traits that accompany the switch from worker sterility to being reproductively active, much less is known regarding the molecular changes that accompany this switch. This review will explore what is known about the genes and molecular pathways involved in the making of laying workers/false queens in the Cape honey bee, Apis mellifera capensis Eschscholtz, through an analysis of the basis for thelytoky in this subspecies, the exocrine glandular chemistry of reproductively dominant workers and what is known about the biosynthesis of their pheromone components. This review will contribute to our understanding of the genetic regulation of thelytoky and the molecular mechanisms that govern reproductive division of labor in honey bees and provide generalizations that may be applicable to other social hymenoptera using this evolutionary fascinating example of worker reproduction.
Influenza-Associated Hospitalizations and Risk of Subsequent Heart Failure Hospital Admissions: A 20-Year Territorywide Registry Study in Hong Kong, China
Authors: Chair Sek Ying , Cheng Ho Yu , Choi Kai Chow , Siow Elaine K C , Cao Xi , Fung Erik
Published: December 2020

Little is known about the risk of hospitalization for cardiovascular disease after influenza infection in younger adults. In a territorywide Hong Kong, China, study using clinical registry data for 1997–2017, we examined the association between influenza-associated hospitalizations and the risk of subsequent hospitalization for heart failure (HHF) in 3 age groups: 18–44 years, 45–65 years, and >65 years. Exposure was defined as any infection with influenzavirus as a primary principal diagnosis for hospitalization, whereas the nonexposed control group comprised persons with hospitalizations for elective orthopedic surgery. Logistic regression was used to determine the risk of HHF within 12 months of hospital discharge for the exposed group versus the nonexposed group. Results showed that influenza-associated hospitalization in the preceding 12 months was associated with increased risk of subsequent HHF in all age groups (all P values < 0.001). Notably, the age group 18–44 years was found to have the highest elevated risk of HHF (adjusted odds ratio = 14.90, 95% confidence interval: 4.48, 49.58). In view of the relatively small number of subsequent HHF episodes in this age group, future studies are needed to confirm the elevated risk in this group and to explore the role of age in the relationship between influenza-associated hospitalization and subsequent HHF.
Measuring Multiple Dimensions and Indices of Nonvaccination Clustering in Michigan, 2008–2018
Authors: Masters Nina B , Delamater Paul L , Boulton Matthew L , Zelner Jon
Published: December 2020

Michigan experienced a significant measles outbreak in 2019 amidst rising rates of nonmedical vaccine exemptions (NMEs) and low vaccination coverage compared with the rest of the United States. There is a critical need to better understand the landscape of nonvaccination in Michigan to assess the risk of vaccine-preventable disease outbreaks in the state, yet there is no agreed-upon best practice for characterizing spatial clustering of nonvaccination, and numerous clustering metrics are available in the statistical, geographical, and epidemiologic literature. We used school-level data to characterize the spatiotemporal landscape of vaccine exemptions in Michigan for the period 2008–2018 using Moran’s I, the isolation index, the modified aggregation index, and the Theil index at 4 spatial scales. We also used nonvaccination thresholds of 5%, 10%, and 20% to assess the bias incurred when aggregating vaccination data. We found that aggregating school-level data to levels commonly used for public reporting can lead to large biases in identifying the number and location of at-risk students and that different clustering metrics yielded variable interpretations of the nonvaccination landscape in Michigan. This study shows the importance of choosing clustering metrics with their mechanistic interpretations in mind, be it large- or fine-scale heterogeneity or between- and within-group contributions to spatial variation.
Beliefs don’t simplify our reasoning, credences do
Authors: Dinges Alexander
Published: December 2020

Doxastic dualists acknowledge both outright beliefs and credences, and they maintain that neither state is reducible to the other. This gives rise to the ‘Bayesian Challenge’, which is to explain why we need beliefs if we have credences already. On a popular dualist response to the Bayesian Challenge, we need beliefs to simplify our reasoning. I argue that this response fails because credences perform this simplifying function at least as well as beliefs do.
Integrated hybrid de novo assembly technologies to obtain high-quality pig genome using short and long reads
Authors: Du Heng , Diao Chenguang , Zhao Pengju , Zhou Lei , Liu Jian-Feng
Published: December 2020

With the rapid progress of sequencing technologies, various types of sequencing reads and assembly algorithms have been designed to construct genome assemblies. Although recent studies have attempted to evaluate the appropriate type of sequencing reads and algorithms for assembling high-quality genomes, it is still a challenge to set the correct combination for constructing animal genomes. Here, we present a comparative performance assessment of 14 assembly combinations—9 software programs with different short and long reads of Duroc pig. Based on the results of the optimization process for genome construction, we designed an integrated hybrid de novo assembly pipeline, HSCG, and constructed a draft genome for Duroc pig. Comparison between the new genome and Sus scrofa 11.1 revealed important breakpoints in two S. scrofa 11.1 genes. Our findings may provide new insights into the pan-genome analysis studies of agricultural animals, and the integrated assembly pipeline may serve as a guide for the assembly of other animal genomes.
Depression Prediction amongst Chinese Older Adults with Neurodegenerative Diseases: A Performance Comparison between Decision Tree Model and Logistic Regression Analysis
Authors: Hao Zhichao , Yang Beichen , Ruggiano Nicole , Ma Yunying , Guo Yuqi , Pan Xiaofu
Published: December 2020

Data analyses using artificial intelligence (AI) have not gained popularity in social work as much as other disciplines. To demonstrate its use, this study focused on Chinese older adults with neurodegenerative diseases (NDs) to (i) develop a prediction model using decision tree model to identify factors associated with depression and (ii) compare the prediction performance of decision tree model with that of logistic regression analysis. Decision tree model processing involved four stages: data collection, data preparation, model development, and result evaluation. An algorithm named Classification and Regression Trees (CARTs) was utilised to grow the decision tree by Python 3.7.1. The performance evaluation was based on accuracy, sensitivity, specificity and Goodness index (G). Seven factors grew the decision tree, including Instrumental Activities of Daily Living (IADLs), Mini-Mental State Examination (MMSE), Health status, Activity of Daily Living (ADL), Gender, Self-rated health change and Age. When compared to logistic regression, the decision tree model had a much better performance in depression prediction. Researchers, practitioners and policymakers need to focus on ways to decrease the vulnerability of depression in Chinese older adults with NDs. Also, the decision tree model can be applied as a referral to other physical or mental diseases prediction and analysis.
The promoting effects of hsa_circ_0050102 in pancreatic cancer and the molecular mechanism by targeting miR-1182/NPSR1
Authors: Hua Surong , Gao Junyi , Li Tong , Wang Mengyi , You Lei , Chen Ge , Han Xianlin , Liao Quan
Published: December 2020

Pancreatic cancer is one of the most lethal tumors across the world with an overall 5-year survival rate of 9%, and great efforts have been devoted in early diagnosis and treatment in the past decades. Competing endogenous RNAs are novel and specific regulatory mechanisms of gene expression, and researches have indicated its important roles in tumor regulation. In this study, we explored the circ-0050102 expression in pancreatic cancer and its impacts on tumor malignant phenotypes and further investigated the correlations among circ-0050102, miR-1182 and NPSR1. Results of real-time quantitative PCR showed that circ-0050102 expressed higher in pancreatic cancers compared with that in adjacent normal tissues. In cell functional experiment, downregulation of circ-0050102 could suppress cell proliferation, migration and invasion ability, boost cell apoptosis and arrest cell cycle in both PANC-1 and CFPAC-1 cells. Furthermore, allogeneic transplantation in nude mice was performed and results showed that the inhibition of circ-0050102 could slow down tumor formation in vivo. Mechanism research suggested that circ-0050102 could downregulate miR-1182, while miR-1182 could not influence the expression of circ-0050102, and miR-1182 could directly target at NPSR1 and suppress it. Moreover, circ-0050102 could reverse the effects of si-NPSR1 on pancreatic cancer cells. In conclusion, we identified that circ-0050102 played an important role in promoting pancreatic cancer by regulating the miR-1182/NPSR1 pathway.