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Al-Ca-Cu三元合金体系中与铝平衡的金属间化合物

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Transactions of Nonferrous Metals Society of China 2024年第5期34卷 1380-1392页

作者： T.K.AKOPYAN T.A.SVIRIDOVA N.A.BELOV N.V.LETYAGIN A.V.KOROTITSKIY National University of Science and Technology MISiS 4 Leninsky pr.Moscow 119049Russia

对三元Al-Ca-Cu合金体系中与铝固溶体平衡的(Al,Cu)_(4)Ca、Al_(27)Ca_(3)Cu_(7)和Al_(8)CaCu_(4)金属间化合物的结构和性能进行全面分析。基于Al4Ca相中部分Al原子被Cu取代,将(Al,Cu)_(4)Ca金属间化合物视为线性化合物。化合物中铜的... 详细信息

对三元Al-Ca-Cu合金体系中与铝固溶体平衡的(Al,Cu)_(4)Ca、Al_(27)Ca_(3)Cu_(7)和Al_(8)CaCu_(4)金属间化合物的结构和性能进行全面分析。基于Al4Ca相中部分Al原子被Cu取代,将(Al,Cu)_(4)Ca金属间化合物视为线性化合物。化合物中铜的溶解度达到10 at.%(19 wt.%),导致化合物的晶格结构、物理和力学性能发生显著变化。例如,化合物的密度从2.22 g/cm^(3)增加到2.79 g/cm^(3),显微硬度从HV 180增加到HV 250。将Al_(27)Ca_(3)Cu_(7)相视为具有严格化学计量比和BaHg11型初始晶体结构的三元化合物,其空间群为Pm3m,晶格参数为8.514Å,密度为3.45 g/cm^(3)。Al_(8)CaCu_(4)相也是严格化学计量比的三元化合物,具有Mn_(12)Th型晶格结构,最高的显微硬度(HV 505)和密度(4.57 g/cm^(3))。属于二元(Al)+(Al,Cu)_(4)Ca相场和准二元(Al)+Al_(27)Ca_(3)Cu_(7)截面的合金,有前景作为新型天然铝基复合材料的基材。

关键词：金属间化合物 Al-Ca合金显微组织晶体结构物理性能力学性能

Design of Biologically Active Macromolecular Ligands and Their Luminescent Complexes with Terbium Ions

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Chinese Journal of Polymer Science 2024年第5期42卷 604-611,I0007页

作者： Tatiana N.Nekrasova Andrei I.Fischer Natalia A.Nesterova Anatoliy V.Dobrodumov Anzhelika V.Garshinina Olga D.Shuvaeva Natalya V.Zakharova Evgenii F.Panarin Institute of Macromolecular Compounds Russian Academy of Sciences31 Bolshoy pr.St Petersburg199004Russia Smorodintsev Research Institute of Influenza Russian Ministry of Health15/17 ul.prof.PopovaSt Petersburg197376Russia

Water-soluble copolymers of p-methacrylamidobenzoic acid(MABA)with neutral comonomers(N-vinylpyrrolidone(VP),N-methyl-N-vinylacetamide(MVAA),N-methacryloyl glucosamine(MAG))and anionic comononer sodium styrene sulfonate(NaSS)were synthesized by radical *** interactions between the pr.pared copolymers and Tb^(3+)ions in aqueous solutions were studied;the significant influence of chemical structure of a comonomer on luminescence intensity of Tb^(3+)complexes with the copolymers was *** luminescence intensity of Tb^(3+)complexes with the copolymers containing N-vinylamide units(VP,MVAA)is three times more intense than that observed for the complexes between Tb^(3+)and MAG-containing *** the case of NaSS-containing copolymers,the luminescence intensity is controlled by the values of binding constants between Tb^(3+)and MABA and the content of MABA units in a *** studied copolymers and their complexes with Tb^(3+)have low cytotoxicity and a pr.nounced antiviral activity against human respiratory syncytial virus.

关键词： Luminescence Water-soluble copolymers Lanthanide complexes Antiviral activity Cytotoxicity

Achieving high strength and rapid degradation in Mg-Gd-Ni alloys by regulating LPSO phase morphology combined with extrusion

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Journal of Magnesium and Alloys 2024年第6期12卷 2312-2326页

作者： Kai Ma Jingfeng Wang Yinhong Peng Chaoneng Dai Yuanlang Pan Ye Wang Danqian Wang Jinxing Wang Yanlong Ma Fusheng Pan College of Materials Science and Engineering Chongqing UniversityChongqing 400044PR China National Engineering Research Center for Magnesium Alloys Chongqing 400044PR China College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 401331PR China College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054PR China

In this study,Mg-13.2Gd-4.3Ni alloys containing continuous bulk-shaped long-period stacking ordered(LPSO),lamellar LPSO,and a small amount of eutectic phase were pr.pared,and the evolution of microstructure at different extrusion temperatures and its influence on mechanical and degradation pr.perties as well as corrosion mechanism were *** before extrusion can effectively pr.mote the pr.cipitation of lamellar LPSO in ***400 with higher volume fraction of non-DRXed grains exhibited higher strength,which was mainly due to strong texture,high dislocation density,and high volume fraction of lamellar *** EX420 with higher volume fraction of DRXed grains showed higher degradation rate,which was mainly due to the higher density of grain *** EX400 exhibited excellent compr.hensive pr.perties with tensile yield strength(TYS)of 334 MPa,ultimate tensile strength(UTS)of 484 MPa and elongation(EL)of 7.4%,ultimate compr.ssive strength(UCS)of 638 MPa and compr.ssive yield strength(CYS)of 443 MPa,degradation rate of 86.1 mg/cm^(2)/h at 93℃in 3 wt.%KCl solution.

关键词： Mg-Gd-Ni alloys LPSO Mechanical pr.perties Degradation rate

Synthesis and microwave absorption performance of heat-treated RF/SiO_(2)aerogels

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Defence Technology（防务技术） 2024年第4期34卷 177-186页

作者： Xinli Ye Hao Yu Kai Zheng Shan Li Xiaomin Ma Bangxiao Mao Junxiong Zhang School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072PR China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057PR China Yangtze River Delta Research Institute of Northwestern Polytechnical University Suzhou 215400PR China National Equipment New Material&Technology(Jiangsu)Co. LtdSuzhou 215400PR China Beijing Xinfeng Aerospace Equipment Co. LtdBeijing 100854PR China School of Textile and Clothing Nantong UniversityNantong 226019PR China

The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious ***,we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel(RF/SiO_(2))with a three-dimensional network structure using sol-gel,atmospheric pr.ssure drying technique as well as heat-treated pr.cesses to achieve enhanced microwave absorption capabilities in the low frequency *** pr.stine RF/SiO_(2)aerogel pr.sented a typical micropores structure with a surface area,porous volume,and density of 146.82 m^(2)/g,62.40%,and 0.28 cm^(3)/g,***,the RF/SiO_(2)aerogel showed an effective absorption bandwidth of 3.56 GHz and a minimum reflection loss value of-46.10 d B at 2.25 mm after being heat-treated at 1500°C,while the maximum effective absorption bandwidth was 3.60 GHz at 2.30 *** intricate three-dimensional networks possessed remarkable impedance matching,multiple attenuation mechanisms,interfacial polarization,and dielectric loss,which were attributed to the exceptional ability to absorb electromagnetic *** offered a fresh appr.ach to creating adaptable and effective microwave absorption materials in military defense.

关键词： RF/SiO_(2) Aerogel Heat-treated Microwave absorption

pr.gress on the application of graphene-based composites toward energetic materials:A review

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Defence Technology（防务技术） 2024年第1期31卷 95-116页

作者： Ting Zhang Xiaoming Gao Jiachen Li Libai Xiao Hongxu Gao Fengqi Zhao Haixia Ma College of Chemistry&Chemical Engineering Yan'an UniversityYan'an 716000ShaanxiPR China School of Chemical Engineering Northwest UniversityXi'an 710069ShaanxiPR China Xi'an Modern Chemistry Research Institute Xi'an 710065ShaanxiPR China

Carbon material is an important additive in energetic *** is a monolayer carbon material in which carbon atoms are arranged in two-dimensional honeycomb structure,who has special optical,electrical,and mechanical ***,the application of graphene-based composites in energetic materials has received extensive *** review mainly summarizes the applications of graphene and graphene-based nanomaterials in energetic *** effects of these materials on the thermal stability,sensitivity,mechanical pr.perty,ignition and combustion of energetic materials were ***,the pr.gress of functionalized modification of graphene has been summarized,including covalent bonding modification and doping *** studies show that graphenebased materials exhibit excellent performances and might emerge as pr.mising candidate for energetic materials.

关键词： Graphene Desensitization Thermal decomposition Catalytic combustion Energetic materials

Microstructure homogeneity and mechanical pr.perties of laser-arc hybrid welded AZ31B magnesium alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1986-1995页

作者： Yongkang Gao Kangda Hao Lianyong Xu Yongdian Han Lei Zhao Wenjing Ren Hongyang Jing School of Materials Science and Engineering Tianjin UniversityTianjin 300350PR China Tianjin Key Laboratory of Advanced Joining Technology Tianjin 300350PR China

Laser-arc hybrid welding of AZ31B magnesium alloy was carried out,the effects of welding parameters on weld formation,microstructure homogeneity and mechanical pr.perties were *** results showed that laser-arc hybrid welding was beneficial to impr.ve the weld formation of magnesium alloy by inhibiting the defect of undercut and *** weld microstructure was mainly columnar grains neighboring the fusion line and equiaxed grains at the weld *** was interesting that the grain size at the upper arc zone was smaller than that at the lower laser zone,with the difference mainly affected by laser power rather than welding current and welding *** welding parameters were optimized as laser power of 3.5 kW,welding current of 100 A and welding speed of 1.5 m/*** this case,the weld was free of undercut and pores,and the tensile strength and elongation rate reached 252 MPa and 11.2%,***,the microstructure homogeneity was illustrated according to the heat distribution,and the evolution law of tensile pr.perties was discussed basing on the weld formation and microstructure characteristics.

关键词： Magnesium alloy Laser-arc hybrid welding Microstructure homogeneity Mechanical pr.perties

Beam oscillating parameters on pore inhibition,recrystallization and grain boundary characteristics of laser-arc hybrid welded AZ31 magnesium alloy

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Journal of Magnesium and Alloys 2024年第6期12卷 2489-2502页

作者： Kangda Hao Yongkang Gao Lianyong Xu Yongdian Han Lei Zhao Wenjin Ren Hongyang Jing School of Materials Science and Engineering Tianjin UniversityTianjin300350PR China Tianjin Key Laboratory of Advanced Joining Technology Tianjin300350PR China

Oscillating laser-arc hybrid welding of AZ31B magnesium alloy was carried out,the effects of beam oscillation parameters on pore inhibition,microstructure,grain boundary characteristics and tensile pr.perties were *** results showed that the pore formation can be inhibited with oscillating frequency higher than 75 Hz and radius smaller than 0.5 *** columnar grains neighboring the fusion line can be broken by the beam oscillation behavior,while the grain growth was pr.moted with the increase of frequency or *** should be noted that the coincidence site lattice(CSL)boundaries were mainlyΣ13b andΣ29 boundaries,which were contributed by{10■2}tensile twins and{11■2}compr.ssion twins,*** total fraction of CSL boundaries reached maximum at radius of 0.25 mm and frequency of 75 Hz,which was also confirmed as the optimized *** this case,the elongation rate increased up to 13.2%,12.8%higher than that of the weld without beam ***,the pore formation and inhibition mechanisms were illustrated according to the state of melt flow and keyhole formation,the abnormal growth was discussed basing on secondary recrystallization,and the relationship among the pore formation,grain size,boundary characteristics and weld toughness were finally established.

关键词： Magnesium alloy Laser-arc hybrid welding Beam oscillation Recrystallization Mechanical pr.perties

Surface demineralized freeze-dried bone allograft followed by reimplantation in a failed mandibular dental implant

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Regenerative Biomaterials 2024年第1期3卷 82-93页

作者： Jing Zhang Jie Wang Jiayi You Xuan Qin Huimin Chen Xiantong Hu Yantao Zhao Yang Xia Jiangsu Key Laboratory of Oral Diseases Nanjing Medical UniversityNanjingJiangsu 210029PR China Jiangsu pr.vince Engineering Research Center of Stomatological Translational Medicine Nanjing Medical UniversityNanjingJiangsu 210029PR China Department of Restorative Dental Sciences Faculty of DentistryThe University of Hong KongHong Kong SARPR China Senior Department of Orthopedics The Fourth Medical Center of PLA General HospitalBeijing100048PR China Beijing Engineering Research Center of Orthopedics Implants Beijing 100048PR China State Key Laboratory of Military Stomatology Xi'an 710032PR China

The removal of a failed implant with high torque causes significant damage to the surrounding tissue,compr.mising bone regeneration and subsequent osseointegration in the defect ***,we report a case of carrier screw fracture followed by immediate implant removal,bone grafting and delayed reimplantation.A dental implant with a fractured central carrier screw was removed using the bur-forceps *** resulting three-wall bone defect was filled with granular surface demineralized freeze-dried bone allograft(SD-FDBA).Cone-beam computerized tomography was performed at 1week,6months and 15months postoperatively and standardized for quantitative *** alveolar bone width and height at 15months post-surgery were about 91%of the original values,with a slightly lower bone density,calculated using the gray value *** graft site was reopened and was found to be completely healed with dense and vascularized bone along with some residual bone *** followed by restoration was performed 8months *** quality of regenerated bone following SD-FDBA grafting was adequate for osseointegration and longterm implant *** excellent osteogenic pr.perties of SD-FDBA are attributed to its human origin,cortical bone-like structure,partly demineralized surfaces and bone morphogenetic pr.tein-2-containing *** investigation with more cases and longer follow-up was required to confirm the final clinical effect.

关键词： dental implant implant failure allogeneic bone bone regeneration reimplantation

The effects of various factors on spontaneous imbibition in tight oil reservoirs

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Petroleum Science 2024年第1期21卷 315-326页

作者： Cheng Liu Tian-Ru Wang Qing You Yue-Chun Du Guang Zhao Cai-Li Dai School of Energy Resources China University of GeosciencesBeijing100083PR China School of Petroleum Engineering China University of PetroleumQingdao266580ShandongPR China

Slickwater fracturing fluids have gained widespr.ad application in the development of tight oil reservoirs. After the fracturing pr.cess, the active components pr.sent in slickwater can directly induce spontaneous imbibition within the reservoir. Several variables influence the eventual recovery rate within this pr.cedure, including slickwater composition, formation temperature, degree of reservoir fracture development, and the reservoir characteristics. Nonetheless, the underlying mechanisms governing these influences remain relatively understudied. In this investigation, using the Chang-7 block of the Changqing Oilfield as the study site, we employ EM-30 slickwater fracturing fluid to explore the effects of the drag-reducing agent concentration, imbibition temperature, core permeability, and core fracture development on spontaneous imbibition. An elevated drag-reducing agent concentration is observed to diminish the degree of medium and small pore utilization. Furthermore, higher temperatures and an augmented permeability enhance the fluid flow pr.perties, thereby contributing to an increased utilization rate across all pore sizes. Reduced fracture development results in a lower fluid utilization across diverse pore types. This study deepens our understanding of the pivotal factors affecting spontaneous imbibition in tight reservoirs following fracturing. The findings act as theoretical, technical, and scientific foundations for optimizing fracturing strategies in tight oil reservoir transformations.

关键词： Tight oil reservoir Spontaneous imbibition Nuclear magnetic resonance Slickwater fracturing fluid Fluid utilization degree