检索结果-南通市图书馆

Effect of Ti and Ta content on the oxidation resistance of Co-Ni-based superalloys

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 351-361页

作者： Yuheng Zhang Zixin Li Yunwei gui Huadong Fu Jianxin xie Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Key la.oratory for Advanced Materials Processing(MOE) University of Science and Technology BeijingBeijing 100083China Beijing la.oratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China

Co-Ni-based superalloys are known for their capability to function at elevated temperatures and superior hot corrosion and thermal fatigue ***,these alloys show potential as crucial high-temperature structural materials for aeroengine and gas turbine hot-end *** previous work elucidated the influence of Ti and Ta on the high-temperature mechanical properties of ***,the intricate interaction among elements considerably affects the oxidation resistance of *** this paper,Co-35Ni-10Al-2W-5Cr-2Mo-1Nb-xTi-(5−x)Ta alloys(x=1,2,3,4)with varying Ti and Ta contents were designed and compounded,and their oxidation resistance was investigated at the temperature range from 800 to 1000℃.After oxidation at three test conditions,namely,800℃for 200 h,900℃for 200 h,and 1000℃for 50 h,the main structure of the oxide la.er of the alloy consisted of spinel,Cr_(2)O_(3),and Al_(2)O_(3)from outside to *** consisting of Ta,W,and Mo formed below the Cr_(2)O_(3)*** interaction of Ti and Ta imparted the highest oxidation resistance to 3Ti2Ta ***,an excessive amount of Ti or Ta resulted in an adverse effect on the oxidation resistance of the *** study reports the vola.ilization of W and Mo oxides during the oxidation process of Co-Ni-based cast superalloys with a high Al content for the first time and expla.ns the formation mechanism of holes in the oxide *** results provide a basis for gaining insights into the effects of the interaction of alloying elements on the oxidation resistance of the alloys they form.

关键词： Co-Ni-based superalloys high-temperature oxidation Ti and Ta elements formation mechanism of holes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis of Pla.ar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine Ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

引用

Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang Qing-Xian xie Xiang Li Chang-Bin Yu Yong-gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key la.oratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The pla.ar-chiral ligands have been widely applied as a cla.s of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of pla.ar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and la.ge steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Pla.ar chirality Nickel Hydroboration Asymmetric synthesis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigating the effect of vola.ility on the hygroscopicities of acetate nanoparticle aerosols by surface pla.mon resonance microscopy

引用

Journal of Environmental Sciences 2024年第4期138卷 167-178页

作者： Bo Yang Zhibo xie Jianguo Liu Huaqiao gui Jiaoshi Zhang Xiuli Wei Zetao Fan Douguo Zhang Key la.oratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China CAS Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Advanced la.er Technology la.oratory of Anhui Province Department of Optics and Optical EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Under high rela.ive humidity(RH)conditions,the release of vola.ile components(such as acetate)has a significant impact on the aerosol *** this work,one surface pla.mon resonance microscopy(SPRM)measurement system was introduced to determine the hygroscopic growth factors(GFs)of three acetate aerosols separately or mixed with glucose at different *** Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) aerosols,the hygroscopic growth trend of each time was lower than that of the previous time in three cyclic humidification from 70% RH to 90% RH,which may be due to the vola.ility of acetic acid leading to the formation of insoluble hydroxide(Ca(OH)_(2) or Mg(OH)_(2))under high RH *** the third calcula.ed GF(using the Zdanovskii-Stokes-Robinson method)for Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) in bicomponent aerosols with 1:1 mass ratio were 3.20% or 5.33% lower than that of the first calcula.ed GF at 90% *** calcula.ed results also showed that the hygroscopicity change of bicomponent aerosol was negatively correla.ed with glucose content,especially when the mass ratio of Mg(CH_(3)COO)_(2) to glucose was 1:2,the GF at 90% RH only decreased by4.67% after three cyclic *** coupled pla.ma atomic emission spectrum(ICP-AES)based measurements also indicated that the changes of Mg^(2+)concentration in bicomponent was lower than that of the *** results of this study reveal thatduring the efflorescence transitions of atmospheric nanoparticles,the organic acids diffusion rate may be inhibited by the coating effect of neutral organic components,and the particles aging cycle will be prolonged.

关键词： Hygroscopic growth Vola.ility Acetate aerosols Nanoparticle aerosol Surface pla.mon resonance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pola.ization Study of Swift J151857.0–572147 with IXPE Observation

引用

Research in Astronomy and Astrophysics 2024年第9期24卷 60-65页

作者： Yu-Shan Ling Fei xie Ming-Yu Ge Fabio la.Monaca Guangxi Key la.oratory for Rela.ivistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key la.oratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China INAF Istituto di Astrofisica e Pla.etologia Spaziali Via del Fosso del Cavaliere 10000133 RomaItaly Dipartimento di Fisica Universitàdegli Studi di Roma“Tor Vergata”Via della Ricerca Scientifica 100133 RomaItaly Dipartimento di Fisica Universitàdegli Studi di Roma“La Sapienza”Piazzale Aldo Moro 500185 RomaItaly

We present an analysis of the Imaging X-ray Pola.imetry Explorer observation from a newly discovered transient source:Swift *** obtained pola.ization degree(PD)and angle are 0.3%±0.3% and -24°±26°respectively in 2-8 keV within 68%confidence level errors,and pola.ization results are below MDP99in all energy bins,with the upper limit on PD of 0.8% in the 2-8 keV energy *** quasi-periodic oscilla.ions(QPOs)are detected in this *** pola.ization and QPO analyses support the hypothesis that the source was in the high soft state,and the results are consistent with predictions for a thin accretion disk model.

关键词： stars:bla.k holes pola.ization X-rays:bursts

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

How to apply ex-vivo split liver transpla.tation safely and feasibly: A three-step approach

引用

World Journal of Gastrointestinal Surgery 2024年第6期16卷 1691-1699页

作者： Dong Zhao Qiu-Hua xie Tai-Shi Fang Kang-Jun Zhang Jian-Xin Tang Xu Yan Xin Jin Lin-Jie xie Wen-gui xie Department of Liver Surgery and Organ Transpla.tation Center Shenzhen Third People’s HospitalThe Second Affiliated HospitalSchool of MedicineSouthern University of Science and TechnologyShenzhen 518112Guangdong ProvinceChina Department of Organ Procurement Organizations Shenzhen Third People’s HospitalThe Second Affiliated HospitalSchool of MedicineSouthern University of Science and TechnologyShenzhen 518112Guangdong ProvinceChina

BACKGROUND Given the current organ shortage crisis,split liver transpla.tation(SLT)has emerged as a promising alternative for select end-stage liver disease *** To introduce an ex-vivo liver graft splitting approach and evaluate its safety and feasibility in *** A retrospective analysis was conducted on the liver transpla.tation data from cases performed at our center between April 1,2022,and May 31,*** study included 25 SLT cases and 81 whole liver transpla.tation(WLT)*** ex-vivo liver splitting was employed for SLT graft procurement in three *** outcomes were determined,including liver function parameters,postoperative complications,and perioperative *** comparisons for categorical variables were performed using theχ²-*** In the study,postoperative complications in the 25 SLT cases included hepatic artery thrombosis(n=1)and pulmonary infections(n=3),with no perioperative *** contrast,among the 81 patients who underwent WLT,complications included perioperative mortality(n=1),postoperative pulmonary infections(n=8),abdominal infection(n=1),hepatic artery thromboses(n=3),portal vein thrombosis(n=1),and intra-abdominal bleeding(n=5).Comparative analysis demonstrated significant differences in ala.ine aminotransferase(176.0 vs 73.5,P=0.000)and aspartate aminotransferase(AST)(42.0 vs 29.0,P=0.004)at 1 wk postoperatively,and in total bilirubin(11.8 vs 20.8,P=0.003)and AST(41.5 vs 26.0,P=0.014)at 2 wk ***,the overall incidence of complications was comparable between the two groups(P>0.05).CONCLUSION Our findings suggest that the total ex-vivo liver graft splitting technique is a safe and feasible approach,especially under the expertise of an experienced transpla.t *** approach developed by our center can serve as a valuable reference for other transpla.tation centers.

关键词： Split liver transpla.tation Transpla.tation Liver splitting Ex-vivo In-situ

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Selective photosynthesis of Z-olefins through crystalline metal-organic cage-initiated expeditious cascade reactions

引用

Carbon Energy 2024年第3期6卷 118-131页

作者： Jia-Ni Lu Yunze Huang Yuan-Sheng Xia Long-Zhang Dong Lei Zhang Jing-Jing Liu la.-gui xie Jiang Liu Ya-Qian la. Jiangsu Key la.oratory of New Power Batteries School of Chemistry and Materials ScienceJiangsu Collaborative Innovation Centre of Biomedical Functional MaterialsNanjing Normal UniversityNanjingChina School of Chemistry South China Normal UniversityGuangzhouChina

The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical ***,fla.mable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial ***,we connect the photocatalytic hydrogen evolution reaction and the semihydrogenation reaction of alkynes in series and successfully realize the high selective production of Z-alkenes using low-cost,safe,and green water as the proton *** the cascade reaction,a series of isomorphic metal–organic cage catalysts(Co_(x)Zn_(8−x)L_(6),x=0,3,4,5,and 8)are designed and synthesized to improve the yield of the photocatalytic hydrogen *** them,Co_(5)Zn_(3)L_(6) shows the highest photocatalytic activity,with a H_(2) generation rate of 8.81 mmol g^(−1) h^(−1).Then,Co_(5)Zn_(3)L_(6) is further applied in the above tandem reaction to efficiently reduce alkynes to Z-alkenes under ambient conditions,which can reach high conversion of>98%and high selectivity of>99%,and maintain original catalytic activity after multiple ***“one-pot”tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z-olefins under mild reaction conditions.

关键词： alkyne semi-hydrogenation hydrogen evolution reaction metal-organic cages photocatalysis Z-olefins

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mass extinctions, their causes and consequences: an interview with Dougla. *** and Shuzhong Shen

引用

National Science Review 2024年第1期11卷 66-70页

作者： Shucheng xie State Key la.oratory of Biogeology and Environmental Geology China University of Geosciences at Wuhan

‘Mass extinctions’ have been a hot topic for several decades. What triggers a mass extinction? How does a mass extinction impact the evolution of life? How does our ecosystem recover after a mass extinction? These questions attracted the interest of both scientists and the public *** spoke to two renowned researchers in the field of mass extinctions: Prof. Dougla. H. Erwin from the National Museum of Natural History of the USA, and Prof. Shuzhong Shen from Nanjing University, China.

关键词： Stratigraphy

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Turbulence Statistics of Thermo-Buoyancy Supercritical Fuel Flow in a Regenerative Cooling Channel

引用

Journal of Thermal Science 2024年第1期33卷 126-137页

作者： SUN Feng xie Gongnan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Department of Thermal Engineering Tsinghua UniversityBeijing 100084China

Active regenerative cooling with supercritical hydrocarbon fuel is considered as the most promising thermal protection *** existence of buoyancy force would lead to strongly anisotropic flow and thermal transport *** is closely rela.ed to the cooling performance of the *** elucidate the mechanisms of turbulent transport,the la.ge eddy simula.ion(LES) was performed to assess turbulence statistics within different turbulence *** results indicated that the buoyancy and inertial force together dominated the change of turbulent ***,the spatial thermal buoyancy effect significantly suppressed the vertical velocity *** is due to the la.inar motion caused by the buoyancy force,thereby weakening the thermal *** the statistics of velocity fluctuation,it was found that the buoyancy force and inertial force greatly weaken the vertical and streamwise velocity fluctuation,*** the statistics of thermal transport,the results pointed out that the near-wall heat transport characteristics need to be paid more *** thickness of the temperature mixing boundary la.er led to the attenuation of vertical heat flux,which inhibited vertical temperature diffusion and predisposed to extreme conditions of heat transfer *** results can enhance the academic understanding of the heat transfer mechanism of supercritical fluids,and give guidance for further applications of thermal protection.

关键词： active regenerative cooling la.ge eddy simula.ion(LES) buoyancy force turbulence statistics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Output feedback stabilization of stochastic high-order pla.ar nonlinear systems with stochastic inverse dynamics and output-constraint

引用

Science China(Information Sciences) 2024年第3期67卷 182-196页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this paper, we solve the output feedback control problem of stochastic high-order pla.ar nonlinear systems with output constraint and stochastic integral input-to-state stability(SiISS) inverse dynamics. By employing a key coordinate transformation, a stochastic nonlinear system with output constraint and SiISS inverse dynamics is converted into an unconstrained system. By skillfully constructing an observer and adopting SiISS small-gain conditions, we develop a new output feedback control design and analysis method, and prove that all the closed-system signals are bounded almost surely, the output constraint is not viola.ed almost surely, and the equilibrium point of the closed-loop system is stochastically asymptotically stable.

关键词： stochastic high-order pla.ar nonlinear system outputconstraint stochastic inverse dynamics output feedbackstabilization stochastic integral input-to-state stability(SiISS)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fixed-time stabilization of output-constrained stochastic high-order nonlinear systems

引用

Science China(Information Sciences) 2024年第4期67卷 5-20页

作者： Ruiming xie Shengyuan XU Nanjing University of Science and Technology School of Automation

In this study, the fixed-time stabilization problem of stochastic high-order nonlinear systems with output constraint and high-order and low-order nonlinearities is addressed. A new coordinate transformation is employed to directly convert output-constrained stochastic systems into an equivalent unconstrained *** fully extracting the characteristics of system nonlinearities and using the stochastic fixed-time stability theorem, a new design and analysis method is constructed to guarantee that the trivial solution of the closed-loop system is stochastically fixed-time stable while fulfilling the output constraint.

关键词： stochastic high-order nonlinear system outputconstraint high-order and low-order nonlinearity fixed-timestabilization finite-time stabilization

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：