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Production induced fracture closure of deep shale gas well under thermo-hydro-mechanical conditions

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Petroleum Science 2024年第3期21卷 1796-1813页

作者： Shi-Ming Wei Yang Xia Yan jin Xu-Yang Guo jing-yu Zi Kai-Xuan qiu Si-yuan Chen College of Science China University of Petroleum(Beijing)Beijing102249China CNOOC Research Institute Ltd Beijing100028China The University of Hong Kong Hong Kong999077China

Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through *** multi-stage fractured horizontal well is the key to exploiting the deep shale gas ***,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas *** this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas *** we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale *** the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture *** with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the *** simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary *** creep and proppant embedment both increase the degree of fracture *** reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the ***,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield *** study is helpful to understand the mechanism of hydraulic fracture ***,it provides the theoretical guidance for maintaining the long

关键词： Shalegas Fracture closure Fluid-solid-heat coupling Discontinuous discrete fracture

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 200°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)

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-yu ZHOU qiu-Yang ZHENG yu LI Cong DING Guang-Jian PENG Zhong-yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Enhancement of polymyxin B1 production by an artificial microbial consortium of Paenibacillus polymyxa and recombinant Corynebacterium glutamicum producing precursor amino acids

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Synthetic and Systems Biotechnology 2024年第1期9卷 176-185页

作者： Hui-Zhong Sun Si-yu Wei qiu-Man Xu Wei Shang Qing Li jing-Sheng Cheng Ying-jin yuan Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering(Ministry of Education) School of Chemical Engineering and TechnologyTianjin UniversityYaguan Road 135Jinnan DistrictTianjin300350PR China Tianjin Key Laboratory of Animal and Plant Resistance College of Life ScienceTianjin Normal UniversityBinshuixi Road 393Xiqing DistrictTianjin300387PR China Department of Pharmaceutical School of Chemical Engineering and TechnologyTianjin UniversityYaguan Road 135Jinnan DistrictTianjin300350PR China

Polymyxin B,produced by Paenibacillus polymyxa,is used as the last line of defense *** this study,exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of polymyxin B analogs of *** CJX518-AC(PPAC)from 0.15 g/L and 61.8%to 0.33 g/L and 79.9%,*** co-culture of strain PPAC and recombinant Corynebacterium glutamicum-leu01,which produces high levels of threonine,leucine,and isoleucine,increased polymyxin B1 production to 0.64 g/*** strains PPAC and ***-leu01 simultaneously inoculated into an optimized medium with 20 g/L peptone,polymyxin B1 production was increased to 0.97 g/***,the polymyxin B1 production in the co-culture of strains PPAC and ***-leu01 increased to 2.21 g/L after optimized inoculation ratios and fermentation medium with 60 g/L *** study provides a new strategy to improve polymyxin B1 production.

关键词： Polymyxin Co-culture Paenibacillus polymyxa Corynebacterium glutamicum Medium optimization Metabolic precursors

Buried interface management via bifunctional NH_(4)BF_(4)towards efficient CsPbI_(2)Br solar cells with a V_(oc)over 1.4 V

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Journal of Energy Chemistry 2024年第2期89卷 364-370,I0009页

作者： Fazheng qiu Ming-Hua Li jinpeng Wu jin-Song Hu School of Materials Science and Engineering NingboTech UniversityNingbo 315100ZhejiangChina Beijing National Laboratory for Molecular Sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190China College of Chemical Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

CsPbI_(2)Br perovskite solar cells(PSCs)have drawn tremendous attention due to their suitable bandgap,excellent photothermal stability,and great potential as an ideal candidate for top cells in tandem solar ***,the abundant defects at the buried interface and perovskite layer induce severe charge recombination,resulting in the open-circuit voltage(V_(oc))output and stability much lower than ***,a novel buried interface management strategy is developed to regulate interfacial carrier dynamics and CsPbI_(2)Br defects by introducing ammonium tetrafluoroborate(NH_(4)BF_(4)),thereby resulting in both high CsPbI_(2)Br crystallization and minimized interfacial energy ***,NH_(4)^(+)ions could preferentially heal hydroxyl groups on the SnO_(2)surface and balance energy level alignment between SnO_(2)and CsPbI_(2)Br,enhancing charge transport efficiency,while BF_(4)^(-)anions as a quasi-halogen regulate crystal growth of CsPbI_(2)Br,thus reducing perovskite ***,it is proved that eliminating hydroxyl groups at the buried interface enhances the iodide migration activation energy of CsPbI_(2)Br for strengthening the phase *** a result,the optimized CsPbI_(2)Br PSCs realize a remarkable efficiency of 17.09%and an ultrahigh V_(oc)output of 1.43 V,which is one of the highest values for CsPbI_(2)Br PSCs.

关键词： Inorganic perovskite Buried interface Defect Stability Open-circuit voltage loss

Unveiling the size effect of nitrogen-doped carbon-supported copper-based catalysts on nitrate-to-ammonia electroreduction

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Nano Research 2024年第4期17卷 2438-2443页

作者： Ran Li Taotao Gao Wenxi qiu Minghao Xie Zhaoyu jin Panpan Li College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Institute for Advanced Study Chengdu UniversityChengdu 610106China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustinTexas 78712USA Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

The electrocatalytic nitrate reduction reaction(NitRR)represents a promising approach toward achieving economically and environmentally sustainable ***,it remains a challenge to regulate the size effect of electrocatalysts to optimize the catalytic activity and ammonia ***,the Cu-based catalysts were tailored at the atomic level to exhibit a size gradient ranging from single-atom catalysts(SACs,0.15–0.35 nm)to single-cluster catalysts(SCCs,1.0–2.8 nm)and nanoparticles(NPs,20–30 nm),with the aim of studying the size effect for the NO_(3)^(-)-to-NH_(3) reduction ***,the Cu SCCs exhibit enhanced metal–substrate and metal–metal interactions by taking advantageous features of Cu SACs and Cu ***,Cu SCCs achieve exceptional electrocatalytic performance for the NitRR with a maximum Faradaic efficiency of ca.96%NH_(3)and the largest yield rate of ca.1.99 mg·h^(-1)·cm^(-2) at-0.5 V *** hydrogen electrode(RHE).The theoretical calculation further reveals the size effect and coordination environment on the high catalytic activity and selectivity for the *** work provides a promising various size-controlled design strategy for aerogel-based catalysts effectively applied in various electrocatalytic reactions.

关键词： nitrate electroreduction ammonia electrosynthesis size effect single-cluster catalyst

Carbon enhanced nucleophilicity of Na_(3)V_(2)(PO_(4))_(3):A general approach for dendrite-free zinc metal anodes

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Journal of Energy Chemistry 2024年第4期91卷 203-212页

作者： Sijun Wang Lingzi Hu Xiaohui Li Dan qiu Shunhang qiu Qiancheng Zhou Wenwen Deng Xiaoying Lu Ze Yang Ming qiu Ying yu Institute of Nanoscience and Nanotechnology School of Physical Science and TechnologyCentral China Normal UniversityWuhan 430079HubeiChina School of Material Science and Engineering Suzhou University of Science and TechnologySuzhou 215000JiangsuChina Faculty of Science and Technology Technological and Higher Education Institute of Hong KongHong KongChina

Zincophilic property and high electrical conductivity are both very important parameters to design novel Zn anode for aqueous Zn-ion batteries(AZIBs).However,single material is difficult to exhibit zincophilic property and high electrical conductivity at the same ***,originating from theoretical calculation,a zincophilic particle regulation strategy is proposed to address these limitations and carbon coated Na_(3)V_(2)(PO_(4))_(3)is taken as an example to be a protective layer on zinc metal(NVPC@Zn).Na_(3)V_(2)(PO_(4))_(3)(NVP)is a common cathode material for Zn-ion batteries,which is *** materials not only offer an electron pathway to help Zn deposition onto NVPC surface,but also enhance the zinc nucleophilicity of Na_(3)V_(2)(PO_(4))_(3).Hence,this hybrid coating layer can tune zinc deposition and resist side reactions such as hydrogen generation and Zn metal ***,a symmetrical battery with NVPC@Zn electrode displays highly reversible plating/stripping behavior with a long cycle lifespan over 1800 h at2 mA cm^(-2),much better than carbon and Na_(3)V_(2)(PO_(4))_(3)solely modified Zn *** the Na_(3)V_(2)(PO_(4))_(3)is replaced with zincophobic Al2O3or zincophilic V2O3,the stability of the modified zinc anodes is also *** strategy expands the option of zincophilic materials and provides a general and effective way to stabilize the Zn electrode.

关键词： Zinc-ion batteries Zinc anode Carbon enhanced nucleophilicity Zincophilic particle regulation

An experimental study on effects of temperature gradient on microstructure of a 308L stainless steel manufactured by directed energy deposition

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Journal of Iron and Steel Research International 2024年第8期31卷 2031-2040页

作者： Ting Dai De-yu Gu yu-wen qiu Wei Guo Hui Ding Yi-wei Sun School of Materials Science and Engineering Jiangsu Key Laboratory of Advanced Metallic MaterialsSoutheast UniversityNanjing 211189JiangsuChina

The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(DED)process was experimentally investigated.A novel cooling system was designed and incorporated to a DED system in order to control the temperature gradient along the deposition direction during *** deposition,the workpiece was placed on a lifting platform,and as the deposition process proceeded,the platform and workpiece were gradually lowered into cooling water so that the temperature gradient along the deposition direction could be controlled and maintained stable during the deposition *** microstructure characterization results indicated that a deposition strategy with higher G and G/R values(where G is temperature gradient and R is solidification rate)produced finer cellular grains that were better aligned with the deposition direction,while a deposition strategy with lower G and G/R values produced columnar grains with larger primary arm spacing and less aligned with the deposition direction.

关键词： Additive manufacturing Directed energy deposition Stainless steel Microstructure Temperature gradient

Intraspecific floral colour variation in three Pedicularis species

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Plant Diversity 2024年第2期46卷 274-279页

作者： qiu-yu Zhang Zhe Chen Hang Sun Yang Niu State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural *** extent of flower constancy is largely determined by the floral traits of co-flowering *** higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower ***,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less *** hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering *** investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis *** was quantified using image-based colour analysis as perceived by *** found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by *** to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community *** may be due to the relatively large interspecific floral colour differences of most co-flowering *** influence of community context on intraspecific variation may be reflected in floral traits other than colours.

关键词： Flower constancy Floral colour variation Plantepollinator interactions Pollinator vision