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Combined use of fly ash and silica to prevent the long-term strength retrogression of oil well cement set and cured at HPHT conditions

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Petroleum Science 2024年第2期21卷 1122-1134页

作者： guo-dong Cheng Xue-Yu Pang Jin-Sheng Sun Zheng-Song Qiu Chuang-Chuang Wang Jian-Kun Qin Ning Li School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Oil and Gas Engineering Research Institute(Tarim Oilfield Company) China National Petroleum CorporationTarim841000XinjiangChina

The long-term strength retrogression of silica-enriched oil well cement poses a significant threat to wellbore integrity in deep and ultra-deep wells, which is a major obstacle for deep petroleum and geothermal energy development. Previous attempts to address this problem has been unsatisfactory because they can only reduce the strength decline rate. This study presents a new solution to this problem by incorporating fly ash to the traditional silica-cement systems. The influences of fly ash and silica on the strength retrogression behavior of oil well cement systems directly set and cured under the condition of 2.0°C and 50 MPa are investigated. Test results indicate that the slurries containing only silica or fly ash experience severe strength retrogression from 2.to 30 d curing, while the slurries containing both fly ash and silica experience strength enhancement from 2.to 90 d. The strength test results are corroborated by further evidences from permeability tests as well as microstructure analysis of set cement. Composition of set cement evaluated by quantitative X-ray diffraction analyses with partial or no known crystal structure(PONKCS) method and thermogravimetry analyses revealed that the conversion of amorphous C-(A)-S-H to crystalline phases is the primary cause of long-term strength *** addition of fly ash can reduce the initial amount of C-(A)-S-H in the set cement, and its combined use with silica can prevent the crystallization of C-(A)-S-H, which is believed to be the working mechanism of this new admixture in improving long-term strength stability of oil well cement systems.

关键词： Fly ash Long-term strength retrogression High temperature Quantitative X-ray diffraction(QXRD) Partial or no known crystal structure(PONKCS)

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Rational design of superior catalysts from topological semimetals with nontrivial energy window

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Rare Metals 2024年第5期43卷 1956-1964页

作者： Min Zhao Li-Rong Wang Wei Liu Ming-Hang Li Ying Liu Xue-Fang Dai guo-dong Liu Xiao-Ming Zhang Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and Engineering ManufacturingHebei University of TechnologyTianjin 300130China

Materials featuring topological energy bands and nontrivial surface states hold significant promise in unlocking unprecedented opportunities for innovating electrocatalytic ***,it remains a challenge to realize superior topological catalysts which can carry both high catalytic activity and excellent catalytic ***,we propose that a family of Ni-based binary materials hosting fantasying topological conjunct-nodalpoint state and a large nontrivial energy window(NEWD)represents an ideal choice for such superior topological catalysts in hydrogen evolution *** presence of conjunct-nodal-points ensures long Fermi arcs on the surface,thereby enabling an extremely high catalytic *** NEWD plays a crucial role in stabilizing the high catalytic activity against external perturbations,such as strain and electron/hole *** roles for conjunctnodal-points and NEWD are substantiated by the observable weakening of catalytic performance during topological phase transitions,which result in the removal of the conjunct-nodal-points,NEWD and their corresponding long Fermi *** work unveils a hidden mechanism and opens a feasible route for developing superior quantum catalysts from novel topology point of view.

关键词： First-principles modeling Topological semimetal Nontrivial surface states Hydrogen evolution reaction

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SDGSAT-1: Capabilities for Monitoring and Evaluating SDG Indicators

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空间科学学报 2024年第4期44卷 677-686页

作者： guo Huadong DOU Changyong LIANG dong JIANG Nijun TANG Yunwei MA Wenyong International Research Center for Big Data for Sustainable Development Beijing 100094 Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094 University of Chinese Academy of Sciences Beijing 100049

SDGSAT-1,the world's first science satellite dedicated to assisting the United Nations 2.30 Sustainable Development Agenda,has been operational for over two and a half *** provides valuable data to aid in implementing the Sustainable Development Goals *** its Open Science Program,the satellite has maintained consistent operations and delivered free data to scientific and technological users from 88 *** program has produced a wealth of scientific output,with 72.papers,including 2. on data processing methods and 44 on applications for monitoring progress toward SDGs related to sustainable cities,clean energy,life underwater,climate action,and clean water and ***-1 is equipped with three key instruments:a multispectral imager,a thermal infrared spectrometer,and a glimmer imager,which have enabled ground-breaking research in a variety of domains such as water quality analysis,identification of industrial heat sources,assessment of environmental disaster impacts,and detection of forest *** precise measurements and ongoing monitoring made possible by this invaluable data significantly advance our understanding of various environmental *** are essential for making well-informed decisions on a local and global *** its application to academic research,SDGSAT-1 promotes global cooperation and strengthens developing countries'capacity to accomplish their sustainable development *** the satellite continues to gather and distribute data,it plays a pivotal role in developing strategies for environmental protection,disaster management and relief,and resource *** initiatives highlight the satellite's vital role in fostering international collaboration and technical innovation to advance scientific knowledge and promote a sustainable future.

关键词： SDGSAT-1 Earth observation Remote sensing SDGs

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In situ synthesis of porous Pt-Pd bimetallic structures for sweat glucose biosensing using dynamic hydrogen bubble template method

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Rare Metals 2024年第7期43卷 3408-3414页

作者： Yi-Wen guo Qian-Hui Wei Fei Wei Hao Liu Hong-Bin Zhao dong Wang Hai-Ling Tu State Key Laboratory of Advanced Materials for Smart Sensing China GRINM Group Co.Ltd.Beijing 100088China Department of Advanced Electronic Materials GRIMAT Engineering Institute Co.Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China GRINM(Guangdong)Institute for Advanced Materials and Technology Foshan 528000China School of Chemical Engineering Northeast Electric Power UniversityJilin 132012China

For the practical application of sweat glucose biosensors,it is crucial to develop a method for modifying the working electrode with noble metals that ensures strong *** this study,we synthesized porous Pt-Pd bimetall... 详细信息

关键词： method bubble porous

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Machine learning-based predictions of current and future susceptibility to retrogressive thaw slumps across the Northern Hemisphere

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Advances in Climate Change Research 2024年第2期15卷 253-264页

作者： Jing LUO guo-An YIN Fu-Jun NIU Tian-Chun dong Ze-Yong GAO Ming-Hao LIU Fan YU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China China Railway Qinghai-Tibet Group Co. LtdXining 810000China University of Chinese Academy of Sciences Beijing 100049China

Retrogressive thaw slumps(RTSs)caused by the thawing of ground ice on permafrost slopes have dramatically increased and become a common permafrost hazard across the Northern Hemisphere during previous ***,a gap remains in our comprehensive understanding of the spatial controlling factors,including the climate and terrain,that are conducive to these RTSs at a global *** machine learning methodologies,we mapped the current and future RTSs susceptibility distributions by incorporating a range of environmental factors and RTSs *** identified freezing-degree days and maximum summer rainfall as the primary environmental factors affecting RTSs *** final ensemble susceptibility map suggests that regions with high to very high susceptibility could constitute(11.6±0.78)%of the Northern Hemisphere's permafrost *** juxtaposed with the current(2.00-2.2.)RTSs susceptibility map,the total area with high to very high susceptibility could witness an increase ranging from(31.7±0.65)%(SSP585)to(51.9±0.73)%(SSP12.)by the *** insights gleaned from this study not only offer valuable implications for engineering applications across the Northern Hemisphere,but also provide a long-term insight into the potential change of RTSs in permafrost regions in response to climate change.

关键词： Retrogressive thaw slump Machine learning Susceptibility map Permafrost Northern Hemisphere

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Natural rubber latex as a potential additive for water-based drilling fluids

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Petroleum Science 2024年第4期21卷 2677-2687页

作者： Jun Yang Guan-Cheng Jiang Jing-Tian Yi Yin-Bo He Li-Li Yang Teng-Fei dong guo-Shuai Wang College of Petroleum Engineering China University of Petroleum (Beijing) National Engineering Research Center of Oil & Gas Drilling and Completion Technology Changqing Drilling General Company CNPC Chuanqing Drilling Engineering Company Limited

The environmental hazards and "carbon footprint" of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals. This paper explored for the first time the interaction mechanism between natural rubber latex(NRL) and bentonite suspensions(BTs) through a series of characterization experiments, as well as the potential applications in water-based drilling fluids(WBDF). The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k) and flow index(n) of BTs, and enhance the shear thinning performance of BTs as pseudo-plastic fluids. In addition, 0.5 w/v% NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles, but also facilitated the compatibility of pressure loss and flow efficiency. The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles, and optimize the particle size distribution and flow resistance of WBDF under the "intercalation-exfoliation-encapsulation" synergistic interaction. Moreover, NRL can improve the rheological properties of WBDF at high temperatures(<150.C), and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake, which ultimately reduces the permeability of the cake and the filtration loss of WBDF.

关键词： Natural materials Water-based drilling fluids Natural rubber latex Bentonite suspensions Filtration loss

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Preoperatively predicting vessels encapsulating tumor clusters in hepatocellular carcinoma:Machine learning model based on contrast-enhanced computed tomography

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 857-874页

作者： Chao Zhang Hai Zhong Fang Zhao Zhen-Yu Ma Zheng-Jun Dai guo-dong Pang Department of Radiology The Second Hospital of Shandong UniversityJinan 250033Shandong ProvinceChina Department of Radiology Qilu Hospital of Shandong UniversityJinan 250014Shandong ProvinceChina Department of Radiology Linglong Yingcheng HospitalYantai 265499Shandong ProvinceChina Department of Scientific Research Huiying Medical Technology Co.LtdBeijing 100192China

BACKGROUND Recently,vessels encapsulating tumor clusters(VETC)was considered as a distinct pattern of tumor vascularization which can primarily facilitate the entry of the whole tumor cluster into the bloodstream in an invasion independent manner,and was regarded as an independent risk factor for poor prognosis in hepatocellular carcinoma(HCC).AIM To develop and validate a preoperative nomogram using contrast-enhanced computed tomography(CECT)to predict the presence of VETC+in *** We retrospectively evaluated 190 patients with pathologically confirmed HCC who underwent CECT scanning and immunochemical staining for cluster of differentiation 34 at two medical *** analysis was conducted on intratumoral and peritumoral regions in the portal vein *** features,essential for identifying VETC+HCC,were extracted and utilized to develop a radiomics model using machine learning algorithms in the training *** model’s performance was validated on two separate test *** operating characteristic(ROC)analysis was employed to compare the identified performance of three models in predicting the VETC status of HCC on both training and test *** most predictive model was then used to constructed a radiomics nomogram that integrated the independent clinical-radiological *** and decision curve analysis were used to assess the performance characteristics of the clinical-radiological features,the radiomics features and the radiomics *** The study included 190 individuals from two independent centers,with the majority being male(81%)and a median age of 57 years(interquartile range:51-66).The area under the curve(AUC)for the combined radiomics features selected from the intratumoral and peritumoral areas were 0.82.,0.788,and 0.680 in the training set and the two test sets.A total of 13 features were selected to construct the *** nomogram,combining clinicalradiological and combined radiomics features could acc

关键词： Hepatocellular carcinoma Vessels encapsulating tumor clusters Intratumoral and peritumoral regions Radiomics features Nomog

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Should we perform sigmoidoscopy for colorectal cancer screening in people under 45 years?

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1248-1255页

作者： Waiian Leong Jia-Qi guo Chun Ning Fei-Fei Luo Rui Jiao dong-Ye Yang Division of Gastroenterology&Hepatology The University of Hong Kong-Shenzhen HospitalShenzhen 518053Guangdong ProvinceChina Department of Accident&Emergency The University of Hong Kong-Shenzhen HospitalShenzhen 518053Guangdong ProvinceChina Department of Anatomical Pathology The University of Hong Kong-Shenzhen HospitalShenzhen 518053Guangdong ProvinceChina Endoscopy Center The University of Hong Kong-Shenzhen HospitalShenzhen 518053Guangdong ProvinceChin

BACKGROUND The strategy for preventing colorectal cancer is screening by colonoscopy,which offers a direct way for detection and removal of adenomatous polyps(APs).American College of Gastroenterology guidelines recommend that people aged≥45 years should undergo colonoscopy;however,how to deal with people aged≤45 years is still *** To compare the prevalence of APs and high-grade neoplasia between the left and right colon in patients≤45 *** A retrospective observational study was conducted at a single tertiary III hospital in *** study included patients aged 18-45 years with undergoing initial colonoscopy dissection and pathological diagnosis AP or high-grade neoplasia between February 2.14 and January *** number of APs in the entire colon while screening and post-polypectomy surveillance in following 1-3 years were *** A total of 3053 cases were *** prevalence of APs in the left and right colon was 55.0%and 41.6%,respectively(OR 1.7,95%CI 1.6-2.4;P2.7%and 0.9%,respectively(OR 3.0,95%CI 2.0-4.6;P2. patients who voluntarily participated in post-polypectomy surveillance in following 1-3 years,and APs were found in 2.6 cases(66.1%);170 cases had 1-3 polyps(52.0%)and 46 cases had>3 polyps(14.1%;OR 0.3,95%CI 0.1-0.6;P<0.05).CONCLUSION This study suggests that flexible sigmoidoscopy would be an optimal approach for initial screening in people aged≤45 years and would be a more cost-effective and safe strategy.

关键词： Adenomatous polyps High-grade neoplasia Colonoscopy Flexible sigmoidoscopy

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Customized heat treatment process enabled excellent mechanical properties in wire arc additively manufactured Mg-RE-Zn-Zr alloys

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International Journal of Extreme Manufacturing 2024年第4期6卷 276-289页

作者： dong Ma Chunjie Xu Shang Sui Yuanshen Qi Can guo Zhongming Zhang Jun Tian Fanhong Zeng Sergei Remennik Dan Shechtman School of Materials Science and Engineering Xi'an University of TechnologyXi'anShaanxi 710048People's Republic of China Xi'an Shechtman Nobel Prize New Materials Institute Xi'an 710048People's Republic of China Xi'an Key Laboratory of Advanced Magnesium Alloy Additive Manufacturing and Precision Forming Xi'anShaanxi 710048People's Republic of China Department of Materials Science and Engineering and Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion Guangdong Technion—Israel Institute of TechnologyShantou 515063People's Republic of China MGM Nobel Prize New Materials Co. LtdTongchuan 727100People's Republic of China Department of Materials Science and Engineering Technion-Israel Institute of TechnologyHaifa 32000Israel Center for Nanoscience&Nanotechnology Hebrew University of JerusalemEdmond J.Safra CampusJerusalem 91904Israel

Customized heat treatment is essential for enhancing the mechanical properties of additively manufactured metallic materials,especially for alloys with complex phase constituents and heterogenous ***,the interrelated evolutions of different microstructure features make it difficult to establish optimal heat treatment ***,we proposed a method for customized heat treatment process exploration and establishment to overcome this challenge for such kind of alloys,and a wire arc additively manufactured(WAAM)Mg-Gd-Y-Zn-Zr alloy with layered heterostructure was used for feasibility *** this method,the optimal microstructures(fine grain,controllable amount of long period stacking ordered(LPSO)structure and nano-scaleβ'precipitates)and the corresponding customized heat treatment processes(52.°C/30 min+2.0°C/48 h)were obtained to achieve a good combination of a high strength of 364 MPa and a considerable elongation of 6.2.,which surpassed those of other state-of-the-art WAAM-processed Mg ***,we evidenced that the favorable effect of the undeformed LPSO structures on the mechanical properties was emphasized only when the nano-scaleβ'precipitates were *** is believed that the findings promote the application of magnesium alloy workpieces and help to establish customized heat treatment processes for additively manufactured materials.

关键词： wire arc additive manufacturing heat treatment Mg-RE-Zn-Zr alloys LPSO structure mechanical properties

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Breaking the efficiency limitations of dissipative Kerr solitons using nonlinear couplers

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 88-94页

作者： Ming Li Xiao-Xiao Xue Yan-Lei Zhang Xin-Biao Xu Chun-Hua dong Guang-Can guo Chang-Ling Zou CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Centerfor Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Department of Electronic Engineering Beijing National Research Center for Information Science and TechnologyTsinghua University Beijing 100084China

Dissipative Kerr solitons(DKS) have long been suffering from poor power conversion efficiency when driven by continuous-wave lasers. By deriving the critical coupling condition of a multimode nonlinear optics system in a generalized theoretical framework,two efficiency limitations of the conventional pump method of DKS are revealed: the effective coupling rate is too small and is also power-dependent. A general approach is provided to resolve this challenge by introducing two types of nonlinear couplers to couple the soliton cavity and CW input through nonlinear processes. The collective coupler opens multiple coupling channels and the self-adaptive coupler builds a power-independent effective external coupling rate to the DKS for approaching the generalized critical coupling condition, which promises near-unity power conversion efficiencies. For instance, a conversion efficiency exceeding 90% is predicted for aluminum nitride microrings with a nonlinear coupler utilizing second-harmonic generation. The mechanism applies to various nonlinear processes, including Raman and Brillouin scattering, and thus paves the way for micro-solitons toward practical applications.

关键词： Kerr frequency comb conversion efficiency nonlinear coupler

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