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Tribological performance of organic cadmium compound as lubricant additive

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 374-378页

作者： HU jian-qiang XIE feng zhu Huan-qin ZHEN Fa-zheng YAO Jun-bing Department of Aviation Oil Air Force Logistics Institute Xuzhou 221000 China Department of Aviation Oil Air Force Logistics Institute Xuzhou 221000 China Department of Aviation Oil Air Force Logistics Institute Xuzhou 221000 China Department of Aviation Oil Air Force Logistics Institute Xuzhou 221000 China First Department Aviation Oil Research Institute Beijing 100000 China

The oil-soluble cadmium dipropyldithiophosphate additive was synthesized. A four-ball tester was used to evaluate the tribological performance of the additive in a mineral oil under different loads and lubricant grease synthesized compared with some commercial additives. The results show that it exhibits excellent antiwear and load-carrying capacities and is better than other additives. The surface analytical tools such as scanning electron microscope (SEM) with energy dispersive X-ray (EDX), X-ray photoelectron spectrometer (XPS) were used to investigate the topography, the compositions, and chemical states of some typical elements on the rubbing surface of worn *** and light topography of worn scar further confirms that the additive shows good antiwear capacities. The results of EDX and XPS analyses indicate that tribochemical mixed protective films consisting of atomic cadmium, sulphides, sulphates and phosphates are formed on the rubbing surface, which contribute to improving the tribological properties of lubricant and grease. Particularly, the soft cadmium film formed plays an important role in improving antiwear properties of oils. Finally, antiwear mechanism of the additive and formation scheme of atomic cadmium was proposed.

关键词： cadmium dipropyldithiophosphate additive extreme pressure antiwear mechanism

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

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China Ocean Engineering 2024年第2期38卷 285-296页

作者： DU Zun-feng zhu Hai-ming YU jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

A dual-function selection system enables positive selection of multigene CRISPR mutants and negative selection of Cas9-free progeny in Arabidopsis

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aBIOTECH 2024年第2期5卷 140-150页

作者： feng-zhu Wang Ying Bao Zhenxiang Li Xiangyu Xiong jian-feng Li State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China

The CRISPR/Cas9 technology revolutionizes targeted gene knockout in diverse organisms including ***,screening edited alleles,particularly those with multiplex editing,from herbicide-or antibiotic-resistant transgenic plants and segregating out the Cas9 transgene represent two laborious *** solutions to facilitate these processes rely on different selection ***,by taking advantage of the opposite functions of a D-amino acid oxidase(DAO)in detoxifying D-serine and in metabolizing non-toxic D-valine to a cytotoxic product,we develop a DAO-based selection system that simultaneously enables the enrichment of multigene edited alleles and elimination of Cas9-containing progeny in Arabidopsis *** five DAOs tested in Escherichia coli,the one encoded by Trigonopsis variabilis(TvDAO)could confer slightly stronger D-serine resistance than other *** expression of TvDAO in Arabidopsis allowed a clear distinction between transgenic and nontransgenic plants in both D-serine-conditioned positive selection and D-valine-conditioned negative *** a proof of concept,we combined CRISPR-induced single-strand annealing repair of a dead TvDAO with D-serine-based positive selection to help identify transgenic plants with multiplex editing,where D-serine-resistant plants exhibited considerably higher co-editing frequencies at three endogenous target genes than those selected by ***,D-valine-based negative selection successfully removed Cas9 and TvDAO transgenes from the survival offspring carrying inherited ***,this work provides a novel strategy to ease CRISPR mutant identification and Cas9 transgene elimination using a single selection marker,which promises more efficient and simplified multiplex CRISPR editing in plants.

关键词： CRISPR Genome editing D-amino acid oxidase Cas9-free Selection marker

Hydrogen peroxide enabled two-dimensional molybdenum trioxide nanosheet clusters for enhanced surface Li-ion storage

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Tungsten 2021年第3期3卷 338-347页

作者： Han Wei Hao-Yu Yang Xiao-Qi Zhang jian-feng zhu Peng-Peng Qiu Wei Luo School of Materials Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021China School of Chemistry and Physics Centre for Materials ScienceQueensland University of Technology(QUT)BrisbaneQLD 4001Australia College of Materials Science and Engineering Institute of Functional MaterialsDonghua UniversityShanghai 201620China

Molybdenum trioxide(MoO3)is regarded as a promising electrode material for lithium(Li)-ion batteries because of its unique layered structure with a high theoretical capacity(~1117 mAh·g-1).Till now,numerous researches have focused on tuning MoO3 morphology to improve its electrochemical ***,the fabrication of MoO3 with a two-dimensional(2D)nanosheet clusters structure has yet been ***,we report a facile one-step solvothermal method to prepare MoO3 nanosheets,of which the morphology can be facilely tuned via the dose of hydrogen *** the experimental results and theoretical calculation suggest that the resultant 2D nanosheets structure could reduce the diffusion paths,which is beneficial for the intercalation of *** a result,the nanosheets assembled Li-ion battery has a reversible specific capacity of 756.1 mAh·g-1 at 0.5·g-1,and maintained at 214.7 mAh·g-1 after 600 cycles at a current density of 1 A·g-1with the Coulombic efficiency as high as 97.17%.

关键词： Molybdenum Trioxide One-step solvothermal method Nanosheets Lithium-ion batteries

Multi-Branch Fault Line Location Method Based on Time Difference Matrix Fitting

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Energy Engineering 2024年第1期121卷 77-94页

作者： Hua Leng Silin He jian Qiu feng Liu Xinfei Huang Jiran zhu School of Electrical and Information Engineering Hunan UniversityChangsha410082China Distribution Network Technical Center State Grid Hunan Electric Power Research InstituteChangsha410007China Technical Center China Energy Construction Group Hunan Thermal Power ConstructionZhuzhou412011China School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha410076China

The distribution network exhibits complex structural characteristics,which makes fault localization a challenging *** when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network *** this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location *** on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were *** time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively *** realize the fault segment location,the least square method was *** was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment ***,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location.

关键词： Multi-branch lines distribution network fault location double-ended traveling wave positioning least square method

Realizing high thermoelectric performance of Cu and Ce co-doped p-type polycrystalline SnSe via inducing nanoprecipitation arrays

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Journal of Advanced Ceramics 2022年第11期11卷 1671-1686页

作者： Yi QIN Tao XIONG jian-feng zhu Yan-ling YANG Hong-rui REN Hai-long HE Chun-ping NIU Xiao-han LI Me-qian XIE Ting ZHAO School of Material Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical EngineeringXi’an Jiaotong UniversityXi’an 710049China

Thermoelectric(TE)performance of polycrystalline stannous selenide(SnSe)has been remarkably promoted by the strategies of energy band,defect engineering,***,due to the intrinsic insufficiencies of phonon scattering and carrier concentration,it is hard to simultaneously realize the regulations of electrical and thermal transport properties by one simple ***,we develop Cu and Ce co-doping strategy that can not only greatly reduce lattice thermal conductivity but also improve the electrical transport *** this strategy,the incorporated Cu and Ce atoms could induce high-density SnSe_(2) nanoprecipitation arrays on the surface of SnSe microplate,and produce dopant atom point defects and dislocations in its interior,which form multi-scale phonon scattering synergy,thereby presenting an ultralow thermal conductivity of 0.275 W·m^(−1)·K^(−1) at 786 ***,density functional theory(DFT)calculations,carrier concentration,and mobility testing reveal that more extra hole carriers and lower conducting carrier scattering generate after Cu and Ce co-doping,thereby improving the electrical *** co-doped Sn_(0.98)Cu_(0.01)Ce_(0.01)Se bulk exhibits an excellent ZT value up to~1.2 at 786 K and a high average ZT value of 0.67 from 300 to 786 *** work provides a simple and convenient strategy of enhancing the TE performance of polycrystalline SnSe.

关键词： polycrystalline stannous selenide(SnSe) Cu and Ce co-doping nanoprecipitation ultralow thermal conductivity thermoelectric(TE)performance

Plutonium utilization in a small modular molten-salt reactor based on a batch fuel reprocessing scheme

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Nuclear Science and Techniques 2024年第4期35卷 15-28页

作者： Xue-Chao Zhao Rui Yan Gui-feng zhu Ya-Fen Liu jian Guo Xiang-Zhou Cai Yang Zou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academies in TMSR Energy System Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

A molten salt reactor(MSR)has outstanding features considering the application of thorium fuel,inherent safety,sustainability,and resistance to ***,fissile material^(233)U is significantly rare at the current stage,thus it is difficult for MSR to achieve a pure thorium-uranium fuel ***,using plutonium or enriched uranium as the initial fuel for MSR is more *** this study,we aim to verify the feasibility of a small modular MSR that utilizes plutonium as the starting fuel(SM-MSR-Pu),and highlight its advantages and ***,the structural design and fuel management scheme of the SM-MSR-Pu were ***,the neutronic characteristics,such as the graphite-irradiation lifetime,burn-up performance,and coefficient of temperature reactivity were calculated to analyze the physical characteristics of the *** results indicate that plutonium is a feasible and advantageous starting fuel for a SM-MSR;however,there are certain shortcomings that need to be *** a 250 MWth SM-MSR-Pu,approximately 288.64 kg^(233)U of plutonium with a purity of greater than 90% is produced while 978.00 kg is burned every ten *** temperature reactivity coefficient decreases from -4.0 to -6.5 pcm K^(-1) over the 50-year operating time,which ensures a long-term safe ***,the amount of plutonium and accumulation of minor actinides(MAs)would increase as the burn-up time increases,and the annual production and purity of^(233)U will *** achieve an optimal burn-up performance,setting the entire operation time to 30 years is ***,more than 3600 kg of plutonium eventually accumulate in the *** research is required to effectively utilize this accumulated plutonium.

关键词： Molten salt fuel Plutonium utilization ^(233)U TRUs mole fraction Temperature feedback coefficient

Macular choroidal thickness in Chinese preschool children: decrease with axial length but no evident change with age

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International Journal of Ophthalmology(English edition) 2019年第9期12卷 1465-1473页

作者： Xian-Gui He Jun-Jie Deng Yao Yin Bo Zhang Shu-Yu Xiong jian-feng zhu Hai-Dong Zou Xun Xu Ling Wang Department of Maternal and Child Health School of Public HealthKey Laboratory of Public Health SafetyMinistry of EducationFudan UniversityShanghai 200032China Department of Preventative Ophthalmology Shanghai Eye Disease Prevention and Treatment CenterShanghai Eye HospitalShanghai 200040China Department of Ophthalmology Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai Key Laboratory of Ocular Fundus DiseasesShanghai Engineering Center for Visual Science and PhotomedicineShanghai 200080China

AIM: To explore the distribution pattern of macular choroidal thickness(ChT) and its association with age as well as refractive status in Chinese ***: School-based, cross-sectional study. A total of 550 healthy preschool children aged 3 to 6 years old from 6 kindergartens were enrolled. Comprehensive ocular examinations, including measurement of visual acuity, axial length, intraocular pressure and slit-lamp examination before cycloplegia, as well as refraction measurement and sweptsource optical coherence tomography(SS-OCT) examination after cycloplegia, were performed. The macular ChT in each sector of the ETDRS grid was measured by the builtin software of ***: The mean central ChT of the participants was 312±59 μm. The mean axial length and spherical equivalent refraction were 22.36±0.72 mm and 1.51±0.83 D, respectively. Axial length increased with age(P0.05). The central ChT of 3-4, 5 and 6 years old children was 314±59 μm, 312±60 μm and 312±59 μm, respectively(P=0.920). No difference was observed in ChT in most of the sectors between genders. No statistical significant difference was observed among different refractive groups(all P>0.05), though the ChT of each sector seemed to be smaller in myopic children. Axial length and weight were the independent factors of central Ch T. Children with longer axial length(β=-21.184, P<0.001) and smaller weight(β=1.502, P=0.041) tended to have thinner ***: In preschool children, the ChT remains relatively stable with age, while a negative association between ChT and axial length existed. This will be helpful to elucidate the characteristics of ChT during the early refractive development.

关键词： preschool children choroidal thickness refractive error optical coherence tomography

Molecular Chain Flexibility and Dielectric Loss at High-Frequency:Impact of Ester Bond Arrangement in Poly(ester imide)s

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Chinese Journal of Polymer Science 2024年第8期42卷 1122-1133页

作者： Ya-Dong Li Hong Li Lu-Kun feng feng Bao Ming-Liang Wang Cai-Zhen zhu Zhao-Hui Zheng Xiao-Bin Ding jian Xu Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100081China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

The evolution of high-frequency communication has accentuated the significance of controlling dielectric properties in polymer ***,it has been theorized that rigid molecular chains lead to lower dielectric ***,the validity of this proposition at high frequencies remains *** scrutinize the correlation between chain flexibility and dielectric properties,we synthesized six poly(ester imide)s(PEIs)with systematically varied molecular chain flexibilities by modifying the ester's substitution on the aromatic *** introduction of ester bonds bestowed all PEI films with a low dielectric dissipation factor(D_(f)),ranging from 0.0021 to 0.0038 at 10 GHz in dry *** dry D_(f)displayed a pattern consistent with volume polarizability(P/V).Unexpectedly,PI-mmm-T,featu ring the most flexible molecular chain,exhibited the lowest dielectric loss under both dry(0.0021@10 GHz)and hygroscopic(0.0029@10 GHz)***,the observed increase in D_(f)after humidity absorption suggests that the high dielectric loss of PEI in applications may be attributed to its hygroscopic *** simulations and characterization of the aggregation structure revealed that the smaller cavities within flexible molecular chains,after close stacking,impede the entry of water *** sacrificing high-temperature resistance,the precursor exhibited enhanced solubility properties and could be processed into high-quality *** research unveils new insights into the relationship between flexibility and highfrequency dielectric loss,offering innovative perspectives on synthesizing aromatic polymers with exceptional dielectric properties.

关键词： 5G communications Poly(ester imide)s Molecular chain flexibility Dielectric properties Humidity absorption