检索结果-南通市图书馆

Residual stress measurement and analysis of siliceous slate-containing quartz veins

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2023年第12期30卷 2310-2320页

作者： Tao Wang Weiwei ye yemeng Tong naisheng jiang Liyuan liu School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by shandong Province and the Ministry of Science and Technology Shandong University of Science and TechnologyQingdao 266590China

Engineering geological disasters such as rockburst have always been a critical factor affecting the safety of coal mine ***,residual stress is considered a feasible method to explain these geomechanical *** this study,electron backscatter diffraction(EBSD)and optical microscopy were used to characterize the rock microcosm.A measuring area that met the requirements of X-ray diffraction(XRD)residual stress measurement was determined to account for the mechanism of rock residual ***,the residual stress of a siliceous slate-containing quartz vein was measured and calculated using the sin^(2) ϕ method equipped with an X-ray *** of microscopic test results showed homogeneous areas with small particles within the millimeter range,meeting the requirements of XRD stress measurement *** was determined as the calibration mineral for slate samples containing quartz *** diffraction patterns of the(324)crystal plane were obtained under different ϕ and φ.The deviation direction of the diffraction peaks was consistent,indicating that the sample tested had residual *** addition,the principal residual stress within the quartz vein measured by XRD was compressive,ranging from 10 to 33 *** maximum principal stress was parallel to the vein trend,whereas the minimum principal stress was perpendicular to the vein ***,the content of the low-angle boundary and twin boundary in the quartz veins was relatively high,which enhances the resistance of the rock mass to deformation and promotes the easy formation of strain concentrations,thereby resulting in residual *** proposed method for measuring residual stress can serve as a reference for subsequent observation and related research on residual stress in different types of rocks.

关键词： residual stress siliceous sand rock microstructure X-ray diffraction electron backscatter diffraction

Separation of Sc_(2)O_(3) from Bayan Obo tailings through an innovative roasting method

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第3期41卷 1071-1076页

作者： Xin-Jun Bao zhi-Jian Wang liu-jiang Xi Ji-Bo liu Zheng-Fu Su Tao Yang Wei Cheng De-Bi zhou Institute for Energy-Storing Materials Research Hunan Rare Earth Metal Material Research InstituteChangsha 410126China College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China School of Metallurgical Engineering Hunan University of TechnologyZhuzhou 412007China

Sc_(2)O_(3)was successfully extracted and separated from Bayan Obo tailings by a CaCl_(2)-reductive carbon powder-combinative roasting *** optimum pro-cess condition was obtained through adjusting specific ef-fect *** is found that Sc_(2)O_(3)with the ratio of 87.51%is leached out under roasting temperature of 800℃for 2 h through adding 73%CaCl_(2),and 20%reductive carbon powder with liquid to solid ratio of ***,the specific reaction mechanism during roasting process was investi-gated by thermogravimetric–differential scanning calorimetry(TG-DSC)and X-ray diffraction(XRD)*** results show that the main phases(SiO_(2),CaF_(2) and naFeSi_(2)O_(6))as well as important phases(LiScSi_(2)O_(6),REFCO_(3)and REPO_(4))would turn into new phases(CaFe-SiO_(4),Fe,Ca_(3)(PO_(4))_(2),naCl,RE_(2)O_(3)and Sc_(2)O_(3))after com-plicated reactions,which effectively break up the original mineral compositions and activate the existing state of containing scandium matter,consequently facilitating the subsequent hydrochloric acid leaching process.

关键词： Bayan Obo tailings Roasting Decomposition Sc_(2)O_(3)

Structural performance of a façade precast concrete sandwich panel enabled by a bar-type basalt fiber-reinforced polymer connector

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2023年第1期17卷 122-137页

作者： Junqi HUANG Qing jiang Xun CHONG Xianguo ye Caihua liu School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei 230009China Anhui Civil Engineering Structures and Materials Laboratory Hefei 230009China

In this study,a novel diagonally inserted bar-type basalt fiber reinforced polymer(BFRP)connector was proposed,aiming to achieve both construction convenience and partially composite behavior in precast concrete sandwich panels(PCSPs).First,pull-out tests were conducted to evaluate the anchoring performance of the connector in concrete after exposure to different ***,direct shear tests were conducted to investigate the shear performance of the *** the test on the individual performance of the connector,five façade PCSP specimens with the bar-type BFRP connector were fabricated,and the out-of-plane flexural performance was tested under a uniformly distributed *** investigating parameters included the panel length,opening condition,and boundary *** results obtained in this study primarily indicated that 1)the bar-type BFRP connector can achieve a reliable anchorage system in concrete;2)the bar-type BFRP connector can offer sufficient stiffness and capacity to achieve a partially composite PCSP;3)the boundary condition of the panel considerably influenced the out-of-plane flexural performance and composite action of the investigated façade PCSP.

关键词： precast concrete sandwich panel basalt fiber reinforced polymer pull-out performance shear performance out-of-plane flexural performance

Feedback and contribution of vegetation, air temperature and precipitation to land surface temperature in the Yangtze River Basin considering statistical analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2023年第1期16卷 2941-2961页

作者： Jinlian liu Xinyao zhou hanya Tang Fengqin Yan Shiwei liu Xuguang Tang zhi Ding Ke jiang Pujia Yu Chongqing Jinfo Mountain Karst Ecosystem national Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Chongqing Key Laboratory of Karst Environment School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China

Land surface temperature(LST),especially day-night LST difference(LSTd-LSTn),is a key variable for the stability of terrestrial ecosystems,affected by vegetation and climate *** the contribution and feedback of vegetation and climate to LST changes is critical to developing mitigation *** on LST,Normalized vegetation index(NDVI),land use(LU),air temperature(AT)and precipitation(Pre)from 2003 to 2021,partial correlation was used to analyze the response of LST to vegetation and *** feedback and contribution of both to LST were further quantifed by using spatial linear relationships and partial derivatives *** results showed that both interannual LST(LSTy)and LSTd-LSTn responded negatively to vegetation,and vegetation had a negative feedback effect in areas with significantly *** was also a major contributor to the decline of *** the advantage of positive partial correlation area of 94.99%,AT became the main driving factor and contributor to LSTy change *** contributed negatively to both LSTy and LSTd-LSTn,with contributions of-0.004℃/y and-0.022℃/y,*** played a decisive role in LST warming of YRB,which was partially mitigated by vegetation and *** present research contributed'to,the,detection,of LST changes and improved understanding of the driving mechanism.

关键词： Land surface temperature vegetation dynamics climate change land use contribution feedback

Transforming liquid flow fuel cells to controllable reactors for highlyefficient oxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid at low temperature

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第3期90卷 621-631,I0014页

作者： ye Qiang Xi liu Denghao Ouyang Zhao jiang Xuebing Zhao Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084China Institute of Applied Chemistry Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina

Highly-efficient oxidation of 5-hydroxymethylfurtural(HMF) to 2,5-furandicarboxylic acid(FDCA) at low temperature with air as the oxidant is still ***,inspired by the respirato ry electron transport chain(ETC) of living cells mediated by electron carriers,we constructed artificial ETCs and transformed liquid flow fuel cells(LFFCs) to flexible reactors for efficient oxidation of HMF to produce FDCA under mild *** LFFC reactor employed an electrodeposition modified nickel foam as an anode to promote HMF oxidation and(VO_(2))_(2)SO_(4) as a cathode electron carrier to facilitate the electron transfer to *** reaction rate could be easily controlled by selecting the anode catalyst,adjusting the external loading and changing the cathodic electron carrier or oxidants.A maximal power density of 44.9 mW cm^(-2) at room temperature was achieved,while for FDCA production,short-circuit condition was preferred to achieve quick transfer of *** a single batch operation with 0.1 M initial HMF,FDCA yield reached 97.1%.By fed-batch operation,FDCA concentration reached 144.5 g L^(-1) with a total yield of 96%.Ni^(2+)/Ni^(3+) redox couple was the active species mediating the electron transfer,while both experimental and DFT calculation results indicated that HMFCA pathway was the preferred reaction mechanism.

关键词： 5-Hydroxymethylfurfural 2 5-Furandicarboxylic acid Electrodeposition Electron transport chain Liquid flow fuel cell

Pre-stack seismic density inversion in marine shale reservoirs in the southern Jiaoshiba area, Sichuan Basin, China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2018年第3期15卷 484-497页

作者： Yuan-Yin Zhang zhi-Jun Jin ye-Quan Chen Xi-Wu liu Lei han Wu-Jun Jin Oil and Gas Survey China Geological Survey Beijing 100083 China State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 100083 China State Energy Center for Shale Oil Research and Development Beijing 100083 China Sinopec Key Laboratory of Shale Oil/Gas Exploration and Production Technology Beijing 100083 China Petroleum Exploration and Production Research Institute Sinopec Beijing 100083 China

For a typical marine shale reservoir in the Jiaoshiba area, Sichuan Basin of China, P-impedance is sensitive for identifying lithology but not suitable for indicating good shale reservoirs. In comparison, density is an important quantity, which is sensitive for identifying the organic-rich mud shale from non-organic-rich mud shale. Due to the poor data quality and incidence angle range, density cannot be easily inverted by directly solving the ill-posed pre-stack seismic inversion in this area. Meanwhile, the traditional density regularizations implemented by directly using the more robust P-impedance inversion tend to be inaccurate for recovering density for this shale reservoir. In this paper, we combine the P-impedance and the minus uranium to construct the pseudo-P-impedance（PIp） at well locations. The PIp is observed to be sensitive for identifying organic-rich mud shale and has a good correlation with density in this area. We employ the PIp–density relation into the pre-stack inversion framework to estimate density. Three types of regularization are tested on both numerical and field data： These are no regularization, traditional regularization and the proposed approach. It is observed that the proposed method is better for recovering the density of organic-rich mud shale in the Jiaoshiba area.

关键词： Density inversion Pseudo-P-impedance Pure P-wave data Regularization

Coherence migration in high-dimensional bipartite systems

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第6期31卷 228-234页

作者： zhi-Yong Ding Pan-Feng zhou Xiao-Gang Fan Cheng-Cheng liu Juan He liu ye School of Physics and Electronic Engineering Fuyang Normal UniversityFuyang 236037China Key Laboratory of Functional Materials and Devices for Informatics of Anhui Educational Institutions Fuyang Normal UniversityFuyang 236037China School of Physics and Optoelectronics Engineering Anhui UniversityHefei 230039China

The conservation law for first-order coherence and mutual correlation of a bipartite qubit state was firstly proposed by Svozil′?k et al.,and their theories laid the foundation for the study of coherence migration under unitary *** this paper,we generalize the framework of first-order coherence and mutual correlation to an arbitrary(m■n)-dimensional bipartite composite state by introducing an extended Bloch decomposition form of the *** also generalize two kinds of unitary operators in high-dimensional systems,which can bring about coherence migration and help to obtain the maximum or minimum first-order ***,the coherence migration in open quantum systems is *** take depolarizing channels as examples and establish that the reduced first-order coherence of the principal system over time is completely transformed into mutual correlation of the(2■4)-dimensional system-environment bipartite composite *** is expected that our results may provide a valuable idea or method for controlling the quantum resource such as coherence and quantum correlations.

关键词： first-order coherence mutual correlation coherence migration high-dimensional

Determining the effect of relative size of sensor on calibration accuracy of TEM cells

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第6期30卷 104-113页

作者： Yun-Sheng jiang Cui Meng han-Bing Jin Ping Wu zhi-Qian Xu liu-Hong Huang Key Laboratory of Particle and Radiation Imaging Ministry of Education Beijing 100084 China Department of Engineering Physics Tsinghua University Beijing 100084 China

The time-domain calibration coefficient of a D-Dot sensor should be identical across various transverse electromagnetic (TEM) cells to comply with the IEEE Std 1309. However, in our previous calibration experiments, poor consistency was observed. The size of D-Dot sensors relative to TEM cells is considered the main reason for this poor consistency. Therefore, this study aims at determining the calibration coefficient of a D-Dot sensor. We calculate the theoretical coefficient as a reference. Practical calibration experiments involve the processing of TEM cells with three different sizes. To observe the response more clearly, corresponding models are constructed and numerical simulations are performed. The numerical simulations and experimental calibration are in good agreement. To determine the calibration accuracy, we quantify the accuracy using the relative error of the calibration coefficient. By comparing the coefficients obtained, it can be concluded that the perturbation error is about 15% when the relative size is over 1/3. Further, the relative size should be less than 1/5 to obtain a relative error below 10%.

关键词： D-Dot Electromagnetic sensor Time-domain calibration Accuracy Numerical simulation

The first CCD photometric study of the open cluster NGC 744

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2018年第11期18卷 89-96页

作者： Kun Wang Li-Cai Deng zhi-Quan Luo Zheng-zhou Yan Qi-Li liu Jin-jiang Sun Qiang zhou Department of Astronomy China West Normal University Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Purple Mountain Observatory Chinese Academy of Sciences

We present the first CCD photometric observations of open cluster NGC 744, as part of the 50 BiN Open Cluster Survey. The color-magnitude diagrams of this cluster were derived from absolute BV RI photometry on a good photometric night. A brief isochrone fitting gives a distance modulus of(m-M)V= 11.58±0.2 and a reddening of E(B-V) = 0.35±0.05 with an age of log t = 8.30±*** carefully examining the BV time-series data, we discovered four new variable stars in a 20′×20′field around the cluster. We classified them as three eclipsing binary stars and one δ Scuti pulsating star,mainly based on the light-curve shape, the detected periods and the positions on the color-magnitude diagrams.

关键词： open clusters and associations: individual(NGC 744) stars: variables: general