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The microstructure of a single crystal superalloy after different aging heat treatments

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Rare Metals 2018年第3期37卷 210-216页

作者： Xiao-Dai Yue Jia-rong Li Xiao-guang Wang Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

To study the influence of aging heat treatments on the microstructure of single crystal superalloys with high content of refractory elements and optimal the aging heat treatment regimes, a single crystal superalloy containing 22 wt% refractory elements was *** show that for the experimental alloy, even the homogenization-solution heat treatment for 25 h cannot homogenize the alloying elements completely. During primary aging heat treatment, γ＇ phase grows larger and turns to regular cubes. Higher aging temperature induces larger γ＇ cubes. For specimens with primary aging heat treated at 1120 ℃,γ＇ morphology does not change apparently during secondary aging heat treatment. For specimens with primary aging heat treatment at 1150 ℃,γ＇phase in interdendrite grows obviously comparing with that in dendrites. By analyzing the precipitating kinetics of γ＇phase, it is found that owning to the dendrite segregation and different aging heat treatment temperatures, γ＇ phase at different regions grows under the control of different factors at different aging heat treatment stages. The two controlling factors that are driving forces of phase transformation and element diffusion rate induce obviously different growth rates of γ＇ phase. As a result, the γ＇-precipitating behaviors are variable based on different solute concentrations and aging temperatures. For advanced single crystal superalloys that are supposed to be used at relatively high temperatures, the final γ＇ size after aging heat treatment is suggested to be close to the crossing point of diffusion controlling curve and driving force controlling curve corresponding to the serving temperature. And then,high-temperature properties can be improved.

关键词： Single crystal superalloy Aging heat treatment γ' precipitation Kinetics

Effects and complications of placement of motility coupling post in porous polyethylene orbital implants

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第6期9卷 464-469页

作者： Hong-guang CUI rong-rong HU Hui-yan LI Wei HAN Department of Ophthalmology the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Objective： To investigate the effects and complications of primary and secondary placements of motility coupling post （MCP） in the unwrapped porous polyethylene orbital implant （PPOI） following enucleation. Methods： We investigated 198 patients who received PPOI implantation following the standard enucleation procedure in the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China, from 2002 to 2004. These patients were subgrouped into PPOI-only patients （112 cases, received PPOI following enucleation）, primary MCP patients （46 cases, received primary placement of MCP during PPOI operation）, and secondary MCP patients （40 cases, received secondary placement ofMCP 6 months after the initial surgery）. Effects and complications among these three groups were compared. Results： The PPOI-only patients took shorter treatment course when compared with other two MCP groups （P〈0.001）, without significant difference noted between the two MCP groups. However, the two MCP groups had better prosthetic motility than PPOI-only group （P〈0.001）, without significant difference between the two MCP groups. In the early stage, 2 eyes in the PPOI-only group and l eye in the primary MCP group had PPOI infection. In PPOI-only group, 3 （2.68%） eyes had PPOI exposure, which occurred after fitting the prostheses; 4 eyes （8.70%） in primary MCP group and 1 eye （2.50%） in secondary MCP had PPOI exposure, which occurred before fitting the prostheses. After prosthesis was fit successfully, the excessive discharge and granuloma were 33.9% and 1.79% in PPOI group-only, 53.3% and 8.9% in primary MCP group, and 52.5% and 7.5% in secondary MCP group, respectively. Conclusion： Both primary and secondary placements of MCP into the PPOI following enucleation can help patients to obtain desirable prosthetic motility, but may be associated with more complications. The primary placement of MCP with skilled operation in selected patients is more recommendable than secondary placemen

关键词： Porous polyethylene orbital implant (PPOI) Motility coupling post (MCP)

About 300 days Optical Quasi-periodic Oscillations in the Long-term Light Curves of the Blazar PKS 2155-304

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Research in Astronomy and Astrophysics 2022年第8期22卷 284-293页

作者： Qi Zheng Xue-guang Zhang Qi-rong Yuan School of Physics and Technology Nanjing Normal UniversityNanjing 210023China

Based on the long-term light curves collected from the Catalina Sky Survey(CSS)(from 2005 to 2013)and the All-Sky Automated Survey for Supernovae(ASAS-SN)(from 2014 to 2018),optical quasi-periodic oscillations(QPOs)about 300 days can be well determined in the well-known blazar PKS 2155-304 through four different methods:the generalized Lomb-Scargle periodogram(GLSP)method,the weighted wavelet Z-transform technique,the epoch-folded method and the redfit *** GLSP determined significance level for the periodicity is higher than 99.9999%based on a false alarm *** redfit provided confidence level for the periodicity is higher than 99%in the ASAS-SN light curve,after considering the effects of red *** on continuous autoregressive process created artificial light curves,the probability of detecting fake QPOs is lower than 0.8%.The determined optical periodicity of 300 days from the CSS and ASAS-SN light curves is well consistent with the reported optical periodicity in the ***,three possible models are discussed to explain the optical QPOs in PKS 2155-304:the relativistic frame-dragging effect,the binary black hole model and the jet precession model.

关键词： (galaxies:)BL Lacertae objects:individual(PKS 2155-304) galaxies:active (galaxies:)quasars:supermassive black holes

Study on Reaction Types and Environment in Different Regions of Diesel Deep Hydrodesulfurization Reactor

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China Petroleum Processing & Petrochemical Technology 2021年第1期23卷 10-20页

作者： Dai Meng Li Shicai Li yang Xu Dahai Ding He Chen guang Guo rong SINOPEC Dalian Research Institute of Petroleum and Petrochemicals Dalian 116045

In this work,the influence of reaction conditions on hydrocarbon distribution and product quality was tested to obtain the rule of variation with different residence time.A semi-experience and semi-mechanism dynamics model was established and *** on the simulation results,the hydrogenation reactor is divided into five regions:the upper two regions are mainly saturated with most of tri-cyclic and bi-cyclic aromatics,and 90%of nitrides are converted,while all simple sulfide and some 4,6-DMDBT compounds undergo transformation *** the lower three regions,the reaction rate of HDS and HDN slows down,while the rate of monocyclic aromatic saturation *** HDS,HDN and HDA rates of the optimized catalyst grading scheme are significantly increased.

关键词： diesel HDS reactor reaction type kinetic model simulation

A review of carbon dioxide disposal technology in the converter steelmaking process

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International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1421-1429页

作者： rong Zhu Bao-chen Han Kai Dong guang-sheng Wei School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Research Center of Special Melting and Preparation of High-end Metal Materials University of Science and Technology BeijingBeijing 100083China

In last decade,the utilization of CO?resources in steelmaking has achieved certain metallurgical effects and the technology is *** this review,we summarized the basic reaction theory of CO2,the CO2 conversion,and the change of energy-consumption when CO2 was introduced in converter steelmaking *** the CO2-O2 mixed injection(COMI)process,the CO2 conversion ratio can be obtained as high as 80%or more with a control of the CO2 ratio in mixture gas and the flow rate of CO2,and the energy is saving and even the energy consumption can be reduced by 145.65 MJ/t under certain *** addition,a complete route of CO2 disposal technology is proposed combining the comparatively mature technologies of CO2 capture,CO2 compression,and liquid CO2 storage to improve the technology of CO2 *** results are expected to form a large-scale,highly efficient,and valuable method to dispose of CO2.

关键词： CO2 utilization carbon dioxide steelmaking enhanced stirring temperature control

A Method of Calculation of the Solar Radio Flux Density for High Spatial Resolution Observations

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Chinese Physics Letters 1999年第3期16卷 223-225页

作者： ZHOU Shu-rong HUANG guang-li Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008

In this paper we present a method of calculation of the flux density of radio source for high spatial resolution solar radio observations,i.e.,according to the observed solar antenna temperature,we make a correction for the K factor of antenna power pattern,then we can obtain values of solar radio *** to models of different brightness temperature distributions of the quiet sun and radio sources,we deduced the expression of the K factor of antenna power pattern,and calculated the fluxes of the quiet sun and slowly varying component emission of radio sources at 22 GHz.

关键词： antenna Solar Spatial

Genetic Diversity of Maize Populations Developed by Two Kinds of Recurrent Selection Methods Investigated with SSR Markers

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Agricultural Sciences in China 2008年第9期7卷 1037-1045页

作者： LI Lu-jiang yang Ke-cheng PAN guang-tang rong Ting-zhao Maize Research Institute Sichuan Agricultural University~Key Laboratory of Crop Genetic Resources and Improvement Ministry of Education Ya＇ an 625014 P.R.China

Two cycles of biparental mass selection （MS） and one cycle of half-sib-S3 family combining selection （HS-S3） for yield were carried out in 2 synthetic maize populations P4C0 and P5C0 synchronously. The genetic diversity of 8 maize populations, including both the basic populations and their developed populations, were evaluated by 30 SSR primers. On the 30 SSR loci, a total of 184 alleles had been detected in these populations. At each locus, the number of alleles varied from 2 to 14, with an average of 6.13. The number and ratio of polymorphic loci in both the basic populations were higher than those of their developed populations, respectively. There was nearly no difference after MS but decreased after HS-S3 in both the basic populations in the mean gene heterozygosity. The mean genetic distance changed slightly after MS but decreased in a bigger degree after HS-S3 in both the basic populations. Analyses on the distribution of genetic distances showed that the ranges of the genetic distance were wider after MS and most of the genetic distances in populations developed by HS-S3 were smaller than those in both the basic populations. The number of genotypes increased after MS but decreased after HS-S3 in both the basic populations. The genetic diversity of intra-population was much more than genetic diversity of inter-population in both the basic populations. All these indexes demonstrated that the genetic diversity of populations after MS was similar to their basic populations, and the genetic diversity was maintained during MS, whereas the genetic diversity of populations decreased after HS-S3. This result indicated that heterogeneity between some of the individuals in the developed populations increased after MS, whereas the populations become more homozygotic after HS-S3.

关键词： maize recurrent selection genetic diversity SSR markers biparental mass selection (MS) half-sib-S3 familycombining selection (HS-S3)

Summer marine heatwaves in the South China Sea:Trend,variability and possible causes

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Advances in Climate Change Research 2022年第3期13卷 323-332页

作者： Hong-Jian TAN rong-Shuo CAI Ren-guang WU Third Institute of Oceanography Ministry of Natural ResourcesXiamen 361005China School of Earth Sciences Zhejiang UniversityHangzhou 310058China

Marine heatwaves(MHWs)have been frequently observed worldwide,causing devastating impacts on marine organisms and ecosystems,but the trend of MHWs is still unclear in the South China Sea(SCS).Here,the long-term trend and inter-annual variability of the summer SCS MHW events are investigated based on the high-resolution daily satellite *** results revealed remarkable increases in the duration,intensity,coverage,and severity during 1982-2019,indicating that the SCS MHW events have become more frequent,intense,extensive,and *** probability ratio of SCS MHW events is four times during the 2010s of that during the *** increasing trend can be largely attributed to the long-term increase in the mean SCS *** inter-annual variability of the SCS MHWs is linked closely to the El Niño and Southern Oscillation,with more/less MHW events occurring during the following summer after the El Niño/La Niña events.A diagnosis of synoptic-scale heat budget suggests that the extreme SCS warming can be explained by the combined effects of positive surface heat flux largely due to the enhanced shortwave radiation and convergence of oceanic advection in association with an anomalous upper-ocean *** effect of surface heat flux seems to be predominant over the large spatial coverage,whereas oceanic heat transport is also important in some specific *** large-scale anticyclonic circulation anomalies over the northwestern Pacific accompanying the westward-extending western Pacific subtropical high during the El Niño decay summers play an essential role in the building-up and persistence of the extreme warming,which has important implications for the prediction of the SCS MHWs.

关键词： Marine heatwaves South China Sea El niño Northwestern pacific anticyclone

Improving WC-Co coating adhesive strength on rough substrate:Finite element modeling and experiment

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Journal of Materials Science & Technology 2020年第2期37卷 1-8页

作者： Adnan Tahir guang-rong Li Mei-Jun Liu Guan-Jun yang Cheng-Xin Li Yu-Yue Wang Chang-Jiu Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an710049China

The adhesive strength in a coating-substrate system is of primary importance for the coating lifetime in ***,the underlying mechanism is not fully understood due to the complex internal structure of composite *** this study,the effect of substrate roughness on the adhesive strength of WCCo coatings was investigated by experiment and *** show that the adhesive strength is significantly affected by the *** the case of the Ra<2μm,the adhesive strength is approximately 35–46 *** the Ra is 4μm,the adhesive strength increases to nearly 60 MPa.A finite element model was developed to correlate the roughness with adhesive *** is found that the predicted values are well consistent with the experimental *** addition,with the increase of the roughness,the residual stress would be changed from concentrated state to widespread state,which decreases the critical stress to result in crack ***’s why a larger roughness can cause a higher adhesive *** study gives understanding on the mechanism of adhesive strength affected by roughness,which contributes to the parameter optimization with better performance.

关键词： Adhesive strength Roughness Lifetime Simulation XFEM Residual stress