bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomistic simulation on frictional response of nanoscratched Al–graphene system
Authors: Zhu Yongchao , Li Na , Zhang Lan , Xia Huimin , Cheng Desen , Ma Huizhong
Published: July 2021

Frictional behaviors of graphene, which have been generally investigated on elastic or rigid substrates, are carefully discussed here in metal–graphene systems through molecular dynamics simulations. The nanoscratched process and topography analysis are conducted to study the friction on a composite surface, where the layer number, embedding depth, and interval of graphene are considered as major factors. The friction coefficient of monolayer graphene on an Al surface is obviously higher than the reported results on an elastic or rigid substrate, while the variety of substrates seems to make no much difference to frictional results on multilayer graphene. Graphene is actually helpful for reducing friction on composite surfaces, but the friction coefficient on composite surfaces will rocket from 0.045 to 0.835 with the rise in the embedding depth of graphene, and this range of data is consistent with experimental values measured on Al–graphene composite coatings. Moreover, a larger distance between graphene may lead to an increase in the overall friction coefficient, which can also be proved by electroplating experiments under a low concentration of graphene.
Data-processing technique for the Taipan “Be-filter” neutron spectrometer at the Australian Nuclear Science and Technology Organisation
Authors: Iles Gail. N. , Rule Kirrily. C. , Peterson Vanessa. K. , Stampfl Anton P. J. , Elcombe Margaret M.
Published: July 2021

There are five filter-analyzer neutron spectrometers available worldwide for scientists to use in order to measure the vibrational density of states in various samples. While Taipan, the thermal spectrometer, has been operated as a triple-axis spectrometer at the Australian Centre for Neutron Scattering since 2010, a beryllium filter analyzer spectrometer was added in 2016. Due to the complex nature of the data post-processing, it has thus far been impossible to fully treat experimental data from scientific measurements taken over the last five years. We have successfully created a robust method of treating data from the Taipan filter-analyzer and present the method on three different samples. The data-treatment process includes correction for the non-linear energy variation of a particular monochromator, removal of higher-order wavelength contamination, and estimation of low-energy multiple-scattering. The steps described here can be utilized by all users of the Australian Nuclear Science and Technology Organisation “Be-filter”—past, present, and future.
Collective excitations in active fluids: Microflows and breakdown in spectral equipartition of kinetic energy
Authors: Kryuchkov Nikita P. , Yurchenko Stanislav O.
Published: July 2021

The effect of particle activity on collective excitations in active fluids of microflyers is studied. With an in silico study, we observed an oscillating breakdown of equipartition (uniform spectral distribution) of kinetic energy in reciprocal space. The phenomenon is related to short-range velocity–velocity correlations that were realized without forming of long-lived mesoscale vortices in the system. This stands in contrast to well-known mesoscale turbulence operating in active nematic systems (bacterial or artificial) and reveals the features of collective dynamics in active fluids, which should be important for structural transitions and glassy dynamics in active matter.
Features of a chaotic attractor in a quasiperiodically driven nonlinear oscillator
Authors: Kruglov V. P. , Krylosova D. A. , Sataev I. R. , Seleznev E. P. , Stankevich N. V.
Published: July 2021

Transition to chaos via the destruction of a two-dimensional torus is studied numerically using an example of the Hénon map and the Toda oscillator under quasiperiodic forcing and also experimentally using an example of a quasi-periodically excited RL–diode circuit. A feature of chaotic dynamics in these systems is the fact that the chaotic attractor in them has an additional zero Lyapunov exponent, which strictly follows from the structure of mathematical models. In the process of research, the influence of feedback is studied, in which the frequency of one of the harmonics of external forcing becomes dependent on a dynamic variable. Charts of dynamic regimes were constructed, examples of typical oscillation modes were given, and the spectrum of Lyapunov exponents was analyzed. Numerical simulations confirm that chaos resulting from the cascade of torus doubling has a close to the zero Lyapunov exponent, beside the trivial zero exponent.
A diagrammatic approach for automatically deriving analytical gradients of tensor hyper-contracted electronic structure methods
Authors: Song Chenchen , Martínez Todd J. , Neaton Jeffrey B.
Published: July 2021

We introduce a diagrammatic approach to facilitate the automatic derivation of analytical nuclear gradients for tensor hyper-contraction (THC) based electronic structure methods. The automatically derived gradients are guaranteed to have the same scaling in terms of both operation count and memory footprint as the underlying energy calculations, and the computation of a gradient is roughly three times as costly as the underlying energy. The new diagrammatic approach enables the first cubic scaling implementation of nuclear derivatives for THC tensors fitted in molecular orbital basis (MO-THC). Furthermore, application of this new approach to THC-MP2 analytical gradients leads to an implementation, which is at least four times faster than the previously reported, manually derived implementation. Finally, we apply the new approach to the 14 tensor contraction patterns appearing in the supporting subspace formulation of multireference perturbation theory, laying the foundation for developments of analytical nuclear gradients and nonadiabatic coupling vectors for multi-state CASPT2.
Reorientational dynamics in highly asymmetric binary low-molecular mixtures—A quantitative comparison of dielectric and NMR spectroscopy results
Authors: Körber Thomas , Pötzschner Björn , Krohn Felix , Rössler Ernst A.
Published: July 2021

Previously, we scrutinized the dielectric spectra of a binary glass former made by a low-molecular high-Tg component 2-(m-tertbutylphenyl)-2′-tertbutyl-9,9′-spirobi[9H]fluorene (m-TPTS; Tg = 350 K) and low-Tg tripropyl phosphate (TPP; Tg = 134 K) [Körber et al., Phys. Chem. Chem. Phys. 23, 7200 (2021)]. Here, we analyze nuclear magnetic resonance (NMR) spectra and stimulated echo decays of deuterated m-TPTS-d4 (2H) and TPP (31P) and attempt to understand the dielectric spectra in terms of component specific dynamics. The high-Tg component (α1) shows relaxation similar to that of neat systems, yet with some broadening upon mixing. This correlates with high-frequency broadening of the dielectric spectra. The low-Tg component (α2) exhibits highly stretched relaxations and strong dynamic heterogeneities indicated by “two-phase” spectra, reflecting varying fractions of fast and slow liquid-like reorienting molecules. Missing for the high-Tg component, such two-phase spectra are identified down to wTPP = 0.04, indicating that isotropic reorientation prevails in the rigid high-Tg matrix stretching from close to TgTPP to Tg1wTPP. This correlates with low-frequency broadening of the dielectric spectra. Two Tg values are defined: Tg1(wTPP) displays a plasticizer effect, whereas Tg2(wTPP) passes through a maximum, signaling extreme separation of the component dynamics at low wTPP. We suggest understanding the latter counter-intuitive feature by referring to a crossover from “single glass” to “double glass” scenario revealed by recent MD simulations. Analyses reveal that a second population of TPP molecules exists, which is associated with the dynamics of the high-Tg component. However, the fractions are lower than suggested by the dielectric spectra. We discuss this discrepancy considering the role of collective dynamics probed by dielectric but not by NMR spectroscopy.
[Ag23Pd2(PPh3)10Cl7]: A new family of synthesizable bi-icosahedral superatomic molecules
Authors: Hossain Sakiat , Miyajima Sayuri , Iwasa Takeshi , Kaneko Ryo , Sekine Taishu , Ikeda Ayaka , Kawawaki Tokuhisa , Taketsugu Tetsuya , Negishi Yuichi
Published: July 2021

Icosahedral noble-metal 13-atom nanoclusters (NCs) can form connected structures, which can be regarded as superatomic molecules, by vertex sharing. However, there have been very few reports on the superatomic molecules formed using silver (Ag) as the base element. In this study, we synthesized [Ag23Pd2(PPh3)10Cl7]0 (Pd = palladium, PPh3 = triphenylphosphine, Cl = chloride), in which two icosahedral 13-atom NCs are connected, and elucidated its geometric and electronic structures to clarify what type of superatomic molecules can be synthesized. The results revealed that [Ag23Pd2(PPh3)10Cl7]0 is a synthesizable superatomic molecule. Single crystal x-ray diffraction analysis showed that the metal–metal distances in and between the icosahedral structures of [Ag23Pd2(PPh3)10Cl7]0 are slightly shorter than those of previously reported [Ag23Pt2(PPh3)10Cl7]0, whereas the metal–PPh3 distances are slightly longer. On the basis of several experiments and density functional theory calculations, we concluded that [Ag23Pd2(PPh3)10Cl7]0 and previously reported [Ag23Pt2(PPh3)10Cl7]0 are more stable than [Ag25(PPh3)10Cl7]2+ because of their stronger superatomic frameworks (metal cores). These findings are expected to lead to clear design guidelines for creation of new superatomic molecules.
Conservation status of common wombats in Tasmania II: population distribution and trends, and the incidence and significance of roadkill
Authors: Driessen Michael M. , Dewar Elise , Carver Scott , Lawrence Clare , Gales Rosemary
Published: July 2021

Understanding species’ distribution, population trends, and the significance of threatening processes are central to the effective conservation and management of wildlife. The island state of Tasmania, Australia, is home to two of the three extant subspecies of common wombat Vombatus ursinus ursinus and V. u. tasmaniensis, both endemic to the state. We provide a comprehensive conservation assessment of both subspecies in Tasmania, providing information on distribution and habitat, population trends and incidence of roadkill. Wombats are widespread in Tasmania, occurring in most vegetation communities, but particularly in agricultural areas, dry eucalypt forests and woodlands, and grasslands. Wombat roadkills are widespread along most major roads, with the interaction of traffic speed and wombat density likely to be one of the main causes of wombat roadkill along roads with low traffic volume. Despite this, and other factors that impact wombats including sarcoptic mange and targeted culling, population indices from standardised spotlight surveys have increased by 2.6 times over the past 36 years for V. u. tasmaniensis on mainland Tasmania and by 4.2 times over the past 27 years for V. u. ursinus on Flinders Island. Based on IUCN criteria for distribution extent and population size and trends, neither subspecies qualifies for up-listing to Threatened. Nevertheless, because of risks to wombats (e.g. disease and roadkill) ongoing monitoring and research into effective mitigation is warranted.
p53 deficiency induces MTHFD2 transcription to promote cell proliferation and restrain DNA damage
Authors: Li Gen , Wu Jun , Li Le , Jiang Peng
Published: July 2021

Significance

Cancer cells acquire distinct metabolic adaptations for survival. However, how metabolic remodeling enables cancer cells to survive genomic instability stress remains poorly understood. This report shows that p53 loss or mutation reprograms folate metabolism through MTHFD2. Moreover, MTHFD2 not only influences reactive oxygen species but also unexpectedly participates in nonhomologous end joining (NHEJ) in response to DNA damage. Down-regulation of MTHFD2 preferably induces apoptosis and cell proliferative arrest in p53-deficient cells but protects p53 wild-type cells by inducing the AICAR-mediated AMPK-p53-p21 activation. Collectively, it reveals both metabolism-dependent and -independent functions of MTHFD2 in controlling p53-dependent cell survival and uncovers a new role for MTHFD2 in NHEJ. MTHFD2 depletion may be a promising therapeutic strategy for the treatment of p53-deficient tumors.
Ecology of the Anthropocene signals hope for consciously managing the planetary ecosystem
Authors: Lehman Clarence , Loberg Shelby , Wilson Michael , Gorham Eville
Published: July 2021

Significance

Human populations so dominate the ecology of the planet that geologists are describing this as the Anthropocene, “the time of humans.” Therefore, understanding the ecology of our time requires understanding our growth, which multiple models have sought to explain. Here we apply a unified model of ecology to understand and summarize historic and prehistoric human populations and provide predictions that concur with some of the more complicated current methods. They reveal that in our societies, and in those of our prehuman ancestors, changes involving cultural evolution have altered fundamental ecological mechanisms, producing three great ecological discontinuities that are successively related to tools, agriculture, and control of fertility. Understanding our ecological development thus far can help guide us into our future.
Adolescent Alcohol use Predicts Cannabis use over a three Year follow-up Period
Authors: Linakis James G. , Thomas Sarah A. , Bromberg Julie R. , Casper T. Charles , Chun Thomas H. , Mello Michael J. , Richards Rachel , Ahmad Fahd , Bajaj Lalit , Brown Kathleen M. , Chernick Lauren S. , Cohen Daniel M. , Dean J. Michael , Fein Joel , Horeczko Timothy , Levas Michael N. , McAninch B. , Monuteaux Michael C. , Mull Colette C. , Grupp-Phelan Jackie , Powell Elizabeth C. , Rogers Alexander , Shenoi Rohit P. , Suffoletto Brian , Vance Cheryl , Spirito Anthony ,   for the Pediatric Emergency Care Applied Research Network.
Published: July 2021

Background: Alcohol and cannabis use frequently co-occur, which can result in problems from social and academic impairment to dependence (i.e., alcohol use disorder [AUD] and/or cannabis use disorder [CUD]). The Emergency Department (ED) is an excellent site to identify adolescents with alcohol misuse, conduct a brief intervention, and refer to treatment; however, given time constraints, alcohol use may be the only substance assessed due to its common role in unintentional injury. The current study, a secondary data analysis, assessed the relationship between adolescent alcohol and cannabis use by examining the National Institute of Alcohol Abuse and Alcoholism (NIAAA) two question screen's (2QS) ability to predict future CUD at one, two, and three years post-ED visit. Methods: At baseline, data was collected via tablet self-report surveys from medically and behaviorally stable adolescents 12–17 years old ( n = 1,689) treated in 16 pediatric EDs for non-life-threatening injury, illness, or mental health condition. Follow-up surveys were completed via telephone or web-based survey. Logistic regression compared CUD diagnosis odds at one, two, or three-year follow-up between levels constituting a single-level change in baseline risk categorization on the NIAAA 2QS (nondrinker versus low-risk, low- versus moderate-risk, moderate- versus high-risk). Receiver operating characteristic curve methods examined the predictive ability of the baseline NIAAA 2QS cut points for CUD at one, two, or three-year follow-up. Results: Adolescents with low alcohol risk had significantly higher rates of CUD versus nondrinkers (OR range: 1.94–2.76, p < .0001). For low and moderate alcohol risk, there was no difference in CUD rates (OR range: 1.00–1.08). CUD rates were higher in adolescents with high alcohol risk versus moderate risk (OR range: 2.39–4.81, p < .05). Conclusions: Even low levels of baseline alcohol use are associated with risk for a later CUD. The NIAAA 2QS is an appropriate assessment measure to gauge risk for future cannabis use.
The Feasibility and Safety of Training Patients in Opioid Treatment to Serve as Peer Recovery Support Service Interventionists
Authors: Kropp Frankie , Wilder Christine , Theobald Jeff , Lewis Daniel , Winhusen T. John
Published: July 2021

Background: The use of peer interventionists may be helpful in addressing problems associated with substance use disorders. However, implementation issues such as training, supervision, and the impact of delivering the intervention on the interventionists themselves require additional examination. This report describes the training methods and peer interventionist outcomes in a pilot study of a single-session Peer Recovery Support Services (PRSS) telephone intervention to facilitate enrollment in medication for opioid use disorder (MOUD) treatment. Methods: This was a secondary analysis of a pilot study testing a PRSS intervention in adults using illicit opioids who reported a recent non-fatal opioid overdose ( N = 80, with 40 PRSS participants). Candidates recruited from MOUD treatment programs were trained to deliver the PRSS intervention. Assessments of adverse events, global health, and peer satisfaction were used to evaluate the effects of serving as an interventionist. Fidelity and proportion of cases enrolling in MOUD were calculated for each interventionist. Results: Four consented candidates were trained to deliver the PRSS intervention to thirty-six study participants (90% PRSS arm). All interventionists successfully maintained fidelity to the PRSS intervention and reported no negative effects. Interventionists experienced differential success in encouraging treatment enrollment ranging from 16%−60% of their cases. Conclusions: This pilot study demonstrates promise in utilizing peer interventionists to deliver a brief PRSS intervention with limited training and no reported negative effects on the interventionists themselves. Factors contributing to the differential success of the interventionists are unclear. Future research on the variable efficacy of peer interventionists is warranted to identify, quantify, and evaluate specific interactional elements associated with peer efficacy. Additionally, further evaluation of training, supervision practices, and the effects of serving as a PRSS interventionist, is needed. Trial Registration: Clinical Trials.gov http://www.clinicaltrials.gov ; Identifier: NCT02922959
Vitamin D3 supplementation reduces serum markers of bone resorption and muscle damage in female basketball players with vitamin D inadequacy
Authors: Stojanović Emilija , Jakovljević Vladimir , Scanlan Aaron T. , Dalbo Vincent J. , Radovanović Dragan
Published: July 2021

This study aimed to investigate the effect of vitamin D3 supplementation at a dose of 4,000 IU/day for 6 weeks on serum levels of: 25‐hydroxyvitamin D [25(OH)D], bone turnover [osteocalcin and carboxy‐terminal telopeptides of crosslinks of type I collagen (CTx‐I)], and muscle damage [lactate dehydrogenase (LDH) and creatine kinase (CK)] in middle adolescent (15‐18 years) and late‐adolescent to early adulthood (19‐30 years) female basketball players with inadequate vitamin D status. Participants (N=24) were randomly assigned in a double‐blind manner into a vitamin D or placebo group. Data were analyzed using separate 2×2x2 mixed ANOVAs with one within‐subjects factor (time) and two between‐subjects factors (condition and age). When a significant interaction was observed, the intra‐group changes were assessed using paired t tests and Hedge's g. Paired t‐tests comparing intra‐group changes in the vitamin D condition revealed a non‐significant large improvement in 25(OH)D (p = 0.06; g = 0.86), non‐significant small decreases in CTx‐I (p = 0.13; g = −0.22) and CK (p = 0.07; g = −0.26), as well as a significant moderate decrease in LDH (p = 0.004; g = −0.74). Paired t‐tests comparing intra‐group changes in the placebo condition revealed a significant moderate decline in 25(OH)D (p <0.001; g = −0.77), as well as significant small increases in CTx‐I (p = 0.04; g = 0.47) and CK (p = 0.04; g = 0.36). Vitamin D3 supplementation at 4,000 IU/day could be effective in reducing bone resorption and muscle damage in female basketball players with inadequate baseline vitamin D, irrespective of age.
Blind map level systematics cleaning: a quadratic estimator approach
Authors: Williams Joel , McCallum Nialh , Rotti Aditya , Thomas Daniel B. , Battye Richard , Brown Michael L.
Published: July 2021

We present the first detailed case study using quadratic estimators (QE) to diagnose and remove systematics present in observed Cosmic Microwave Background (CMB) maps. In this work we focus on the temperature to polarization leakage. We use an iterative QE analysis to remove systematics, in analogy to de-lensing, recovering the primordial B-mode signal and the systematic maps. We introduce a new Gaussian filtering scheme crucial to stable convergence of the iterative cleaning procedure and validate with comparisons to semi-analytical forecasts. We study the limitations of this method by examining its performance both on idealized simulations and on more realistic, non-ideal simulations, where we assume varying de-lensing efficiencies. Finally, we quantify the systematic cleaning efficiency by presenting a likelihood analysis on the tensor to scalar ratio, r, and demonstrate that the blind cleaning results in an un-biased measurement of r, reducing the systematic induced B-mode power by nearly two orders of magnitude.
J-PAS: forecasts for dark matter-dark energy elastic couplings
Authors: Figueruelo David , Aparicio Resco Miguel , Teppa Pannia Florencia A. , Beltrán Jiménez Jose , Bettoni Dario , Maroto Antonio L. , Abramo L. Raul , Alcaniz Jailson , Benitez Narciso , Bonoli Silvia , Carneiro Saulo , Cenarro Javier , Cristóbal-Hornillos David , Dupke Renato A. , Ederoclite Alessandro , López-Sanjuan Carlos , Marín-Franch Antonio , Marra Valerio , Mendes de Oliveira Claudia , Moles Mariano , Sodré Laerte , Taylor Keith , Varela Jesús , Vázquez Ramió Héctor
Published: July 2021

We consider a cosmological model where dark matter and dark energy feature a coupling that only affects their momentum transfer in the corresponding Euler equations. We perform a fit to cosmological observables and confirm previous findings within these scenarios that favour the presence of a coupling at more than 3σ. This improvement is mainly driven by cluster counts from Planck Sunyaev-Zeldovich data that we include as a certain prior. We subsequently perform a forecast for future J-PAS data and find that clustering measurements will permit to clearly discern the presence of an interaction within a few percent level with the uncoupled case at more than 10σ when the complete survey, covering 8500 sq. deg., is considered. We found that the inclusion of weak lensing measurements will not help to further constrain the coupling parameter. For completeness, we compare to forecasts for DESI and Euclid, which provide similar discriminating power.
Preliminary Study of Reduced Graphene Oxide Cobalt Sulfide Synthesis
Authors: Supriyanto A , Kawuri K R , Ramelan A H , Wahyuningsih S , Hanif Q A , Harjana  , Fathoni H A
Published: July 2021

Graphene is a material that has amazing electrical and optical properties. This research will discuss the effect of adding Cobalt Sulfide (CoS) on the reduction of graphene oxide (RGO) by using variations in the CoS ratio to improve the electrochemical properties of RGO. Graphene oxide (GO) is reduced by adding (Co(NO3)2.6H2O, thiourea (CH4NS) and added with ethylenediamine, then all materials reacted via solvothermal process. RGO that has been successfully synthesized will be characterized to determine the structural and chemical characteristics of the synthetic material by using X-Ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FTIR), Scanning Electron Microscopyy (SEM), and Spectrophotometer UV-Vis. According to the results characterizations there are many differences on the optical characteristic and morphology on each phase of GO, RGO and RGO CoS.
Water balance response of permafrost-affected watersheds to changes in air temperatures
Authors: Debolskiy Matvey V , Alexeev Vladimir A , Hock Regine , Lammers Richard B , Shiklomanov Alexander , Schulla Joerg , Nicolsky Dmitry , Romanovsky Vladimir E , Prusevich Alexander
Published: July 2021

Observations show increases in river discharge to the Arctic Ocean especially in winter over the last decades but the physical mechanisms driving these changes are not yet fully understood. We hypothesize that even in the absence of a precipitation increase, permafrost degradation alone can lead to increased annual river runoff. To test this hypothesis we perform 12 millennium-long simulations over an idealized hypothetical watershed (1 km2) using a distributed, physically based water balance model (Water flow and Balance Simulation Model, WaSiM). The model is forced by both a hypothetical warming defined by an air temperature increase of 7.5 ∘C over 100 years, and a corresponding cooling scenario. To assess model sensitivity we vary soil saturated hydraulic conductivity and lateral subsurface flow configuration. Under the warming scenario, changes in subsurface water transport due to ground temperature changes result in a 7%–14% increase in annual runoff accompanied by a 6%–20% decrease in evapotranspiration. The increase in runoff is most pronounced in winter. Hence, the simulations demonstrate that changes in permafrost characteristics due to climate warming and associated changes in evapotranspiration provide a plausible mechanism for the observed runoff increases in Arctic watersheds. In addition, our experiments show that when lateral subsurface moisture transport is not included, as commonly done in global-scale Earth System Models, the equilibrium water balance in response to the warming or cooling is similar to the water balance in simulations where lateral subsurface transport is included. However, the transient changes in water balance components prior to reaching equilibrium differ greatly between the two. For example, for high saturated hydraulic conductivity only when lateral subsurface transport is considered, a period of decreased runoff occurs immediately after the warming. This period is characterized by a positive change in soil moisture storage caused by the soil moisture deficit developed during prior cooling.
Effect of water content on oxidation activity of residual coal in Goaf
Authors: Zhang Peiwei , Zhao Wenbin , Chen Kun , Liu Yang
Published: July 2021

In order to study the effect of water on the oxidation activity of residual coal in goaf, FTIR experiment was used to analyze the effect of water quality on the oxidation functional groups of coal under different soaking time; The experimental results show that based on the change trend of oxidation functional groups of coal in acidic and alkaline environment, the change of acidity and alkalinity of water will lead to the increase of - Oh peak area of coal sample; With the increase of soaking time of weak alkaline mine water, the content of Oh in coal sample is higher; The peak area of main oxidation functional groups of coal first increases and then decreases with the increase of soaking time.
The Analysis on Concrete-Face Rock-Fill Dam by Finite Element Method
Authors: Zhang Jianyou , Du Rong
Published: July 2021

Numerical model of Concrete-Face Rock-Fill Dam is built based on the large finite element software ANSYS, three- dimensional finite e1ement theory of numerical simulation is applied to Concrete-Face Rock-Fill Dam. The displacement of the dam and the stress of the concrete-faced are obtained. The deformation and the stress distribution of Concrete-Face Rock-Fill Dam in construction and impoundment are analyzed. The research result will be very useful to Concrete-Face Rock-Fill Dam’s construct and design in the future.
Research on refined gas governance model in Pingdingshan mining area
Authors: Chen Yutao
Published: July 2021

Aiming at the characteristics of large mining depth, low permeability, high gas pressure and high in-situ stress in the Pingdingshan mining area, a refined mine gas management model was proposed, which mainly included the implementation of gas drainage standardization, drilling video, and one drilling and one project. Taking the 13th Pingmei Coal Mine as an example, the effect analysis since the implementation of refined gas treatment was carried out, and it was found that the gas concentration was increased from 5% to 36%, and the scalar volume of extraction was increased from 1.0m3/min to 7m3/min, and the decay cycle had increased from 7 days to more than 50 days, and the gas governance cycle had been shortened by 90 days by promoting the refined gas governance model. The research results show that the proposed mine gas fine control model has good applicability.
Study on the water cut characteristics and its adjustment methods at the late stage of polymer flooding in Block A-1
Authors: Chi Lijuan
Published: July 2021

Block A-1 has been developed for three years by polymer flooding, and now it encountered a reoccurrence of water cut. Based on a large number of dynamic and static data, the rules of water cut and the potential area of residual oil in the late stage of polymer injection were systematically analyzed. It was found that the water cut in Block A-1 could be categorized into three types, namely, U, W, and V types. The residual oil was comprehensively evaluated based on the water cut profiles, and moreover, the adjustment methods were proposed to control the water cut rate at the late stage of polymer injection in Block A-1. The methodologies established in this paper has successfully controlled the water cut rate as well improved the oil recovery of Block A-1.
An overview of path planning algorithms
Authors: Tang Zhuozhen , Ma Hongzhong
Published: July 2021

This paper reviews the basic concepts of path planning, classifies environmental modeling methods, analyzes the significance of V2X environment modeling, and summarizes the existing path planning algorithms. Different algorithm can be adjusted in time according to different environments to improve the efficiency of path planning. In addition, according to the advantages and disadvantages of different algorithms, each algorithm is fused, which can effectively avoid the shortcomings of each algorithm and improve the efficiency of the planning algorithm.
Hydrocarbon accumulation conditions and models in fault -depression superimposed basin: a case in Longfengshan area in Songliao basin, China
Authors: Fan Jie , Jiang Youlu , Zhang Kuihua , Zeng Zhiping , Gong Yajun , Gao Jianxiong , Zhu Jianfeng
Published: July 2021

Songliao Basin develops typical fault-depression superimposition dual structure in vertical. So far, the depression sequence has achieved continuous stable yield of oil and gas, while it is of great significance to deepening exploration of hydrocarbon in faulted sequence. Taking the new Longfengshan Area as the research object, in light of the analysis of source rock condition, source of hydrocarbon, passage system, caprock condition and accumulation period, the dynamic hydrocarbon accumulation process is recovered, and hydrocarbon accumulation models are established. Research shows that K1sh Formation source rock in the northern depression zone has good hydrocarbon generation capacity, which provides high quality source condition. What is more, effective configuration between sealing faults and connected sandstone provides important hydrocarbon migration and accumulation condition. Meanwhile, the top of K1yc3 Formation mudstone caprock has good fault-caprock configuration, which provides good hydrocarbon preservation condition. The hydrocarbon accumulation model of study area can be summarized as “source rock in sag zone supplies hydrocarbon, fault-sandstone configuration controls hydrocarbon migration, faults-caprocks configuration controls hydrocarbon accumulation” pattern which embodies the characteristics of “rapid vertical transporting by faults, fault-sandbody configuration, caprocks control hydrocarbon accumulation” in the stage of fault-depression transition and “sealing by faults, sandstone conducts laterally- faults, caprocks control hydrocarbon accumulation” in the stage of depression.
Development characteristics and petroleum geological significance of tearing faults in Hashan area
Authors: Xue Yan , Wang Qianjun , Xiong Wei , Yu Hongzhou , Xiao Xiongfei , Wang Yuxin , Wang Yue , Zhou Jian
Published: July 2021

Hashan area is part of piedmont thrust belt in northwestern Junggar basin. By studying its structural characteristics, it is found that there are three different deformation sections along the strike of tectonic belt. It is considered that the development of tearing faults is the main reason for controlling the difference of structural deformation in different sections of Hashan area. In order to study the characteristics and petroleum geological significance of tearing faults, the identification and structural characteristics of tearing faults are studied, combined with the analysis of petroleum geological conditions, its petroleum geological significance is found out.The results showed that: The tearing faults in the Hashan area are usually developed in the position where the strike of the main reverse fault changes. The strike is mainly NW-trending and is roughly perpendicular to the long axis of the main structure. The terrain on both sides of the fault has obvious dislocation or belongs to different terrains, and is mostly presented flower-like structure or steep cliff on the profile. The lateral compression during the formation of the piedmont zone leads to the differential nappe of different structural parts of the same block, which is the main reason for the formation of tearing faults in Hashan area. The late tearing faults of nearly north-south direction in Hashan area communicated deep source rocks downward, Jurassic blanket sand upward and formed traps laterally, which played an important role in controlling hydrocarbon accumulation.
The character and origin of sequence architecture in the arid climate zone: A case of the Lower Submember of the Fourth Member of Shahejie Formation in the Bonan Sub-Sag
Authors: Xu Qisong , Wang Yongshi , Ma Lichi , Meng Tao , Bi Junfeng , Jiang Chao
Published: July 2021

The early Paleogene experiences a prolonged global hyperthermal period. The Lower Submember of the Fourth Member of Shahejie Formation (Es4x) of early Paleogene deposits a set of unique red sequence with influences of global hyperthermal events. Many researches focus on paleoclimate reconstruction of global hyperthermal period. However, few researches concern sequence architecture and sedimentary response in this extreme climate background. As the sequence architecture and sedimentary response record the paleoclimate, the character and origin of them can provide signals to reconstruct paleoclimate. Thus, this research investigates paleoclimate, character and origin of sequence architecture to reveal inter relationships and provide basis for paleoclimate reconstruction. The climate evolution and its sediment supply responses controlled the development of sequence architecture and reconstructed the different sedimentary responses. The periodic evolution of climate and sediment supply response results in the T-R cycle and sand body enrichment in the TST stage. The sand bodies of the TST stage concentrate in the LTST stage as frequency and amplitude of fluctuations are higher. The LTST stage developed large scale sand bodies with longest distance transportation in. Subsequently, the drier and stable climate continues to decreases sediment supply during the RST stage. Sand bodies shrunk to the edge of Sub-sag.
Analysis on dynamic characteristics of polymer flooding and influencing factors of flooding effect in Daqing Oilfield
Authors: Jia Lingzhu
Published: July 2021

Polymer flooding technology after years of painstaking research, from the initial pilot field experiment, to the later industrial field experiment, now has entered the stage of industrialization. During this period, a series of technical applications in the field of polymer flooding were established, forming a supporting system for polymer flooding, laying a solid foundation for the large-scale application of polymer flooding, which is widely used in the oilfield. And polymer flooding technology has achieved remarkable results in Daqing Oilfield. This paper analyzes the dynamic characteristics of polymer flooding technology in Daqing Oilfield and the influencing factors of displacement effect.
Chemical Characteristics and Evolution of Shallow groundwater of Yellow River and Tuhai River Basin in Huimin area, Shandong Province, China
Authors: Wang Kuifeng , Xie Wei , Liu Wen , Wang Wei , Zhang Taiping
Published: July 2021

Based on data characteristics of hydrochemistry and hydrogen and oxygen stable isotopes of large area groundwater samples from two rivers basin (Yellow river and Tuhai River) in Huimin, Shandong, this paper makes a deep discussion of hydrochemical characteristics, recharge source and hydrogeochemical evolution process of groundwater. The results show that the shallow groundwater is alkalescent, hydrochemical type is Cl·HCO3—Na·Mg, total dissolved solids (TDS) vary from 751∼6501mg/L, mainly >1000mg/L, and the average is 1824mg/L; the main resources of shallow groundwater are atmospheric precipitation and Yellow River seepage; the groundwater is jointly effected by rock weathering and evaporation concentration, the Na+, Ca2+, Mg2+, Cl– and SO4
2- in the groundwater have very high correlation with TDS and total hardness. The extensive existence of Br indicates an inseparable relation between groundwater and seawater i.
The applications of Grey system theory in predicting the outburst of coal and gas in Linhuan Coal Mining
Authors: Cheng Hao
Published: July 2021

Coal and gas outburst is one of mine serious natural disasters. Grey cluster assessment of the grey system theory is used to predict the outburst of coal and gas in Huaibei Coal Mining Group Linhuan Coal Mining so as to have effective prevention and control on this kind of accident. This method will research the influence outstanding of various factors combined systematic analysis, through comparing the conclusion, thereby improving the forecasting accuracy. This method has the advantages of dynamic, predict accurately reflects exactly the mine coal and gas outburst rule, for the prevention and control of coal and gas outburst is ensured.
Study on Intelligent Inspection Scheme of Concrete Component Quality Based on Multivariate Data Link
Authors: Wang Wanqi
Published: July 2021

With the rapid development of information technology, construction project management has obtained better technical support, and intelligent site system has been widely used to improve management efficiency and quality. First, based on the intelligent site system, this paper elaborates the overall framework and detection objectives of intelligent detection in view of the current situation of concrete construction quality detection in railway construction projects. Second, based on the intelligence detection, taking the quality of concrete components as the research object, the resource management detection, technological process detection, component quality detection and process monitoring and detection schemes are proposed, which provide an important detection guarantee for the quality of concrete components in terms of safety and strength.
Study on The Technical Plan of Continuous Beam Rotation Construction Monitoring and Early Warning
Authors: Wu Sitong , Qian Jin
Published: July 2021

The rotating construction of the bridge is the better choice, the continuous beam rotation intelligent monitoring system was built by the Academy of Railway Sciences and was developed and applied based on the “Smart Construction Site” project of the Huzhou-Hangzhou Railway. Firstly, this article introduces the system. The system is based on Beidou’s high-precision satellite positioning solution system to calculate the attitude of the bridge during the construction of the rotating body. The key stress level and change of the bridge can be obtained through the stress sensor,which can obtain the response trend of the pontic structure, and effectively control the stress damage and dangerous points in the first time. Secondly, it continuously moitors the temperature and humidity of the rotating bridge, wind speed, bridge pier strain, inclination angle, and rotation angle in real time during the entire course of the bridge rotation to ensure the safety of construction. Thirdly, points out the location of the sensor buried in the foundation pit during the bridge construction process. Finally, the principle and composition of the bridge health warning technology scheme based on BIM technology are introduced, and its significance and advantages are summarized. Provides solutions and experience for the long-term monitoring of bridges in rotating construction.
Overview of Tunnel Boring Machine Dynamic Balance Construction
Authors: Gao Huan , Liu Chang , Man Ke
Published: July 2021

The concept of Tunnel Boring Machine (TBM) dynamic balance construction has been put forward here, i.e. 5S TBM construction. Among them, Suitability refers to the matching degree between TBM equipment and geological conditions, the matching degree between TBM equipment and construction scheme, the dynamic adjustment ability of TBM in the face of different geological conditions, and the induction and analysis of geological exploration results. Sustainability refers to TBM construction is continuous, not interrupted by uncontrollable factors, the operation of each process is continuous and the connection is compact, the speed of each stage is basically balanced. And the maintenance time, the number of tool changes and the frequency of tool changes are basically the same. Speedy refers to under the same geological conditions, maintain a consistent and rapid tunneling speed. When the geological condition is good, the equipment completion rate and tunneling footage maintain efficient, while for bad geological conditions, the tunneling footage and support time maintain relatively efficient. And with a reasonable material transport scheme, reasonable slag discharge scheme, reasonable support scheme, equipment integrity rate and pure tunneling time utilization ratio. Safety refers to the safety of staffs and TBM equipment in the process of construction and maintenance of equipment, standardized operation of each process, advanced detection of geological prediction. Safeguarded of environmental protection refers to TBM equipment itself and excavated chambers and tunnels should be kept clean. Long working conditions need ventilation, cooling, noise removal, vibration reduction measures, sanitary conditions measures. Furthermore, combined with the II bid of Water Supply Project in Jilin, the TBM construction has been realized with the average monthly intact rate of 94.7%, the highest reached to 98.06%, the average utilization rate of 56.85%, the maximum utilization rate of 75.6%, and the average monthly footage of more than 600 meters. It shows that the operation method of TBM dynamic balance construction has been well verified in this project.
Study on the Soil Structure and Construction Technology of Large Span Double-Arch Tunnel Entrance
Authors: Dong Jiansong
Published: July 2021

In the construction process of tunnel engineering, the construction of the entrance section is one of the crucial procedures. How to improve the construction efficiency and ensure the stability of the tunnel entrance section needs to be considered. Based on the project of a double-arch tunnel, this paper studies the construction techniques of the entrance of the urban double-arch tunnel with a large span. Based on the numerical simulation, it is proved that the construction of tunnel entrance by opening up a cross passage is feasible.
Application of Drilling Strain Analysis Technology in Mine Dynamic Geological Disaster Monitoring
Authors: Li Guilin , Wu Qinzheng , Liu Huanxin , Cheng Li , Liu Yang , Wang Xi
Published: July 2021

This article applies the borehole strain observation technology to mine dynamic disaster monitoring for the first time, and uses the fractal box dimension to quantitatively analyse the time history change characteristics of borehole strain data and its correlation with rock bursts. The article uses the drilling multi-parameter test device to test in the mine, and judges the stress distribution by collecting the drilling parameter data obtained from the test hole of the working face of the test point. The study found that the application of borehole strain observation technology to mine dynamic disaster monitoring can directly and accurately record the micro-dynamic change process of rock mass in the area before and after the occurrence of rock burst. The fractal box dimension can quantify the complex changes and evaluation of strain data. Abnormal degree of water tide distortion.
Mechanical Properties and Energy Conservation Analysis for The New Connection of The Fabricated Shear Wall
Authors: Fan Handuo , Zhang Yueguo , Zhang Yichao , Jiang Haowen , Du Linghang , Liu Qikai
Published: July 2021

In order to investigate a reliable reinforcement connection form for the assembly nodes of the fabricated reinforced concrete shear walls with joint seams, and explore a reinforced bars lap splice method with easy control of construction quality, a new type of reinforced bars lap splice method with the additional X-shaped reinforcement at the assembly nodes is proposed. By changing the width of the assembly nodes, three fabricated shear wall models were designed. By using Abaqus finite element analysis software, the full-range numerical simulations of its mechanical properties under static load were carried out to study the behaviors of the new reinforced bars lap splice method, which were compared with the behaviors of the cast-in-place monolithic shear wall with the same design parameters and analyzed. The results show that the additional X-shaped reinforcement changed the force transmission path of the reinforced bars lap splice at the assembly nodes and reduced the cross-sectional stress of lap splice area, and improved the reliability of the weak part of the fabricated shear walls. The method also reduced the difficulty of assembling fabricated shear wall structure. Comparing the fabricated shear walls in the same assembly position, the analyses show that the reinforced bars lap splice with the additional X-shaped reinforcement is not sensitive to joint seam width, which can realize the shear walls can assemble with small seam width, and effectively improves prefabrication rate.
Research and application of micropile technology on expansive soil and saline soil in geotechnical engineering
Authors: Xie Xiao , Wang Luyao
Published: July 2021

Micropile has the advantages of flexible pile arrangement, small construction area, strong applicability to soil, convenient and fast construction, etc. Therefore, it has been widely used in many fields of geotechnical engineering in recent years. The unique advantages of the micropile gradually emerged in some special occasions. Based on the collection of domestic and foreign literatures, this article makes a more comprehensive summary and introduction of the concept, characteristics, materials, classification and application development history of micropiles. The work of this article will provide a theoretical basis for the theoretical research and engineering application related to the micropile technology.