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Bonding-unsaturation-dependent superconductivity in P-rich sulfides

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Matter and Radiation at Extremes 2022年第4期7卷 81-88页

作者： Xing Li Xiaohua Zhang Yong Liu Guochun Yang State Key Laboratory of Metastable Materials Science and Technology and Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Northeast Normal University Changchun 130024China

The covalent frameworks found in certain compounds,such as the S–H skeleton in H3S and the H cage in LaH10,play an essential role in their superconductivity.These compounds have the feature of bonding unsaturation(a deficiency of electrons in their covalent bonding)in common.Developing an understanding of the relationship between superconductivity and bonding unsaturation in these materials can provide new ideas for the design of superconducting materials.In this work,we explored the high-pressure phase diagram of binary P–S compounds using first-principles swarm structural calculations.In addition to the previously reported P2S and P3S structures,we identified that P5S,P8S,and P11S also have a common structural character of six-coordinated octahedral networks;however,their bonding unsaturation are distinct due to the different valence electron numbers and unequal ratios of P and S atoms.These features provide an ideal model for exploring the bonding-unsaturation dependence of superconductivity.We estimated the average bonding unsaturation of these P-rich compounds based on the valence electron numbers and the coordination numbers of the central P/S atoms.Interestingly,the resultant average bonding unsaturation was found to be proportional to the predicted superconducting transition temperature.This finding was also verified in MH9(M=Y,Th,and Pr)and doped H3S(Si,C,and P)compounds.Our work provides an opportunity to gain a deeper understanding of bonding-unsaturation-dependent superconductivity.

关键词： saturation bonding superconductivity

An analytical model for evaluating the dynamic response of a tunnel embedded in layered foundation soil with different saturations

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 663-681页

作者： Di Honggui Guo Huiji Zhou Shunhua Wang Binglong He Chao Zhang Xiaohui Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji UniversityShanghai 201804China The Technical Center of Shanghai Shentong Metro Group Co. Ltd.Shanghai 201103China Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety Tongji UniversityShanghai 201804China

This paper proposes an analytical model for evaluating the dynamic response of an underground railway tunnel in layered foundation soil with different saturations.The soil is modeled as layered media,and the circular tunnel lining is modeled as an infinite Flügge cylindrical shell.The separation of variables method is used to solve the motion equation of the shell,and the wave equation of the soil is solved using the Helmholtz decomposition theorem.A dynamic matrix reflecting the wave vectors of soil layers is established using the transfer matrix method.Based on boundary conditions,the tunnel-soil model is coupled using the transformation method of plane wave functions and cylindrical wave functions.The proposed model is validated by comparison with existing tunnel models,and the effects of saturation and the layered properties of soil on the dynamic response of a layered tunnel-soil system is demonstrated via case studies.

关键词： tunnel unsaturated soil saturation transfer matrix method wave function transformation

Smartphones and traffic signals:A quantitative assessment for phone usage behavior on performance of signalized intersections

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第4期10卷 611-632页

作者： Wael ElDessouki Abdulrahman AlManeea Department of Transportation and Traffic Engineering Imam Abdulrahman Bin Faisal UniversityDammam 31441Kingdom of Saudi Arabia

Modern smartphones differ vastly from classic cellphones with enormous capabilities,changing cellphones from making phone calls and short messages to pocket-sized computers with full internet connectivity.The downside of modern phone evolution is changing drivers’behavior and phone usage addiction.Several researchers have investigated the safety implications of phone usage while driving on accidents risk.Nevertheless,the effect of phone usage on the performance of traffic facilities did not receive equal attention.Hence,this research aims to study the impact of smartphone usage on traffic signal operations.The parameters considered in the study were drivers’activity while waiting at the signal,startup lost time,and saturation flow rate.The study team covered 25 intersections in the study area,observed the activities of over 6800 drivers while waiting at the signal,and recorded their corresponding discharge headways.The study team then supplemented field data with a behavioral survey questionnaire for drivers living in the study area to interpret field observations.Finally,the collected data were processed and analyzed,resulting in mathematical models for the relationship between the reduction in saturation flow rate and the red time interval.The team found two primary conclusions.The study’s first finding was that the traditional concept for estimating startup lost time adopted by the highway capacity manual(HCM)appears inaccurate.The field results revealed that the lost times caused by other distracted drivers upstream in the queue were comparable to the estimated startup lost time following the HCM method for estimating startup lost time.The second finding was that the reduction in saturation flow rate at the traffic signal is an exponential function of the red time interval,reducing the overall capacity for the intersection and increasing the average delay.Finally,the authors suggest mitigating the problem and making recommendations for future research.

关键词： Signals Smartphone saturation Flow Discharge Headway

Experimental Examination of Velocity-Models in Estimating Gas Hydrate saturation in Sediments

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地学前缘 2009年第S1期16卷 224-225页

作者： Gaowei Hu~(1,3),Yuguang Ye~(2,3),Jian Zhang~(2,3),Jiasheng Wang~1 1.Faculty of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China. 2.Key Laboratory of Marine Hydrocarbon Resources and Environment Resources,the Ministry of Land and Resources,Qingdao 266071,China 3.Qingdao Institute of Marine Geology,the Ministry of Land and Resources,Qingdao 266071,China

Elastic velocities(v_p and v_s)have been widely used in estimating gas hydrate saturation in void spaces of sediments.The commonly used models are empirical equations or some physically based models,such as Wyllie’s time average,Effective Medium Theory (EMT),Modified Biot-Gassmann Theory by Lee (BGTL),etc.These equations or models are selective to distinct conditions.In order to evaluate the app-

关键词： gas hydrates saturation elastic velocities models applicability

Influence of water saturation on propagation of elastic waves in transversely isotropic nearly saturated soil

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2003年第6期4卷 73-80页

作者：李保忠蔡袁强 Department of Civil Engineering Zhejiang University Hangzhou 310027 Department of Civil Engineering China

Biot’s two phase theory for fluid saturated porous media was applied in a study carried out to investigate the influence of water saturation on propagation of elastic wave in transversely isotropic nearly saturated soil. The characteristic equations for wave propagation were derived and solved analytically. The results showed that there are four waves: the first and second quasi longitudinal waves (QP1 and QP2), the quasi transverse wave (QSV) and the anti plane transverse wave (SH). Numerical results are given to illustrate the influence of saturation on the velocity, dispersion and attenuation of the four body waves. Some typical numerical results are discussed and plotted. The results can be meaningful for soil dynamics and earthquake engineering.

关键词： saturation Transversely isotropic Nearly saturated Dispersion Attenuation

Logging-based assessment of low-resistivity oil zones:A case study from Sudan

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能源地球科学(英文)

能源地球科学(英文) 2023年第2期4卷 82-90页

作者： Li Chunmei Wu Furong Zang Dianguang Peng Cai Guo Hongxi Li Jie Southwest Geophysical Research Institute BGP Inc.China National Petroleum CorporationChengduChina Petro China Southwest Oil&Gas Feild Company ChengduChina

The reservoirs in the N oilfield in Sudan feature a complex sedimentary environment,which has led to a widespread development of low-resistivity oil zones,accounting for as high as 37%of the total oil zones.In this case,a large number of oil zones will be misinterpreted using conventional methods.Based on the analysis of the core data and logging curves of the study area,this study concludes that the lowresistivity oil zones are formed mainly due to the high irreducible water saturation caused by the high content of illite and smectite and complex pore structure,the additional electrical conductivity induced by clay minerals,and the difference in formation water salinity between the oil zones and water zones.Furthermore,four methods are proposed to qualitatively identify these oil zones and water zones,namely the relationship analysis of five reservoir properties,cross-plotting of sensitive parameters,analysis of pressure testing data,and multi-well correlation.Furthermore,the study quantitatively calculates the initial oil saturation using the capillary pressure data,thus avoiding the conventional empirical saturation formulas depending on electrical resistivity and solving the difficulty in calculating oil saturation of low-resistivity oil zones.Finally,precise logging processing and interpretation of 95 wells in the study area are conducted using the above-mentioned comprehensive assessment system for low-resistivity oil zones.As a result,59 oil zones are newly discovered in 43 wells.Moreover,it is recommended that 17 oil zones in 12 wells should be tested,of which 11 oil zones have been tested as recommended,all proven to be high production oil zones after perforation.The coincidence rate of logging interpretation increases from 75%to 94.3%,and the original oil in place(OOIP)increases by 57.42 million barrels.All these indicate that the assessment system proposed is suitable for low-resistivity zones.

关键词： Low-resistivity oil zone Cause analysis Qualitative identification J-function saturation

Experimental Study of Thermal-Hydraulic-Mechanical Coupling Behavior of High-Performance Concrete

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Fluid Dynamics & Materials Processing 2023年第9期19卷 2417-2430页

作者： Wei Chen Wenhao Zhao Yue Liang Frederic Skoczylas School of Civil Engineering Architecture and EnvironmentHubei University of TechnologyWuhan430068China CNRS Centrale LilleUMR9013-LaMcube-Laboratoire de Mécanique Multiphysique et MultiéchelleUniversitéde LilleLilleF-59000France

The design of an underground nuclear waste disposal requires a full characterization of concrete under various thermo-hydro-mechanical-chemical conditions.This experimental work studied the characterization of coupled thermo-hydro-mechanical effects using concretes made with cement CEM I or CEM V/A(according to European norms).Uniaxial and triaxial compression under 5 MPa conﬁning pressure tests were performed under three dif-ferent temperatures(T=20℃,50℃,and 80℃).The two concretes were dried under relative humidity(RH)to obtain a partially saturated state of approximately 70%.The results showed that the effects of water saturation and conﬁning pressure are more important than that of temperature.Drying in high RH at different target tempera-tures led to an increase in uniaxial and triaxial strength but drying at 105℃ had a negative effect on the strength and Young’s modulus.Oven drying caused microcracking in the concrete.The microcracks deeply inﬂuenced the thermal damage to the material,affecting its mechanical behavior.The triaxial strength clearly increased due to the presence of conﬁning pressure.Moreover,an important inﬂuence of cement type was observed on the mechanical properties;the concrete based on CEM V/A had a greater porosity than CEM I,and aﬁner pore struc-ture appeared due to the presence of mineral admixtures.

关键词： Concrete temperature saturation uniaxial compression triaxial compression

EFFECT OF ANTHROPOGENIC CO_2 ON THE pH AND THE saturation STATES OF CALCITE AND ARAGONITE OF SEAWATER

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Chinese Journal of Oceanology and Limnology 1997年第2期15卷 145-149页

作者：陈镇东王树伦 hylo.life.uiuc.edu

Growth of phytoplankton, zooplankton and probably most other marine organisms as well, is likely to be affected by the pH of seawater. Growth of calcareous shells and skeletons is less likely to be affect ed by the saturation states of calcite and aragonite but the dissolution is. The increase of CO2 in the oceans due to burning of fossil fuel and clearing of forests is decreasing the pH of seawater and the degress of saturation for calcite and aragonite worldwide. This paper presents the results of the first attempt to estimate the vertical distribution of anthropogenic CO2, and the decreases in pH and the degrees of saturation of calcite and aragonite in seawater near Taiwan. Most ef fects are very small except for the possible dissolution of aragonite on the upper continental slope starting around 2050 AD.

关键词： anthropogenic CO2 pH calcite aragonite degree of saturation saturation

Intensity Dependence of Cesium D_(2)-Line saturation Spectra

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Chinese Physics Letters 1996年第6期13卷 424-427页

作者： LI Yi-min CHEN Xu-zong GAN Jian-hua JI Wang-xi HUA Jing-shan YANG Dong-hai WANG Yi-qiu Department of Radio-Electronics Peking UniversityBeijing 100871

The intensity dependence of the cesium D_(2)-line saturation absorption spectra in a nearly zero magnetic field was investigated theoretically and experimentally.By using rate equations the D_(2)-line saturation absorption spectra were calculated,which agree reasonably well with the experimental results.The variation of the spectra with different cell lengths was also reported and explained with theoretical calculation.

关键词： calculation. spectra saturation