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Effect of Hf on Stress Rupture Properties of DD6 Single Crystal Superalloy After Long Term Aging

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Journal of Iron and Steel Research(International) 2012年第7期19卷 66-70页

作者： shi Zhen-xue LI Jia-rong liu shi-zhong National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095China

The specimens of the second generation single crystal superalloy DD6 with different Hf contents were prepared in the directionally solidified furnace with a high temperature gradient. The long term aging of the specimens after full heat treatment was performed at 1040℃for 800 h. The effect of Hf on the microstructure and stress rupture properties under 980℃/250 MPa of the alloy after long term aging was investigated. The results show that the γ＇ coarsening and rafting and no topologically close packed phase （TCP） are observed in the microstructures of DD6 alloy with different Hf contents after aged at 1 040℃ for 800 h. It indicates that DD6 alloy with different Hf contents all possesses good microstructure stability. With increasing Hf content the rupture life after long term aging turns shorter and the elongation represents the increasing first and decreasing afterwards. The fracture mechanism of the alloy with different Hf contents at 980℃/250 MPa all shows dimple model. The influence of the microstructures on the stress rupture properties of the alloy is also discussed.

关键词： DD6 single crystal superalloy stress rupture property long term aging

Influence of Cast Dimension on Rotary Bending High Cycle Fatigue Properties of Single Crystal Superalloy

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Journal of Iron and Steel Research(International) 2013年第12期20卷 98-102页

作者： shi Zhen-xue HAN Mei liu shi-zhong LI Jia-rong Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

Samples of DD3 single crystal superalloy with different dimensions were cast in the directionally solidified furnace with high temperature gradient. The effect of cast dimension on the rotary bending high cycle fatigue （HCF） properties of the alloy was investigated at 800 ℃ in ambient atmosphere. SEM was used to examine the fracture sur- face and fracture mechanism of the all.oy. The results show that the rotary bending HCF properties of the alloy de- creases with increasing cast dimension. The cast dimension has little effect on the HCF fracture mechanism of the al loy. The HCF fracture mechanism of the alloy with different cast dimensions is all quasi-cleavage fracture. The fa- tigue cracks initiated on the surface or near the surface of the specimens. The crack would propagate along { 111} oc- tahedral slip planes. Typical fatigue arc and striation formed on fatigue crack steady propagation. The degenera- tion of HCF properties is due to the increase of dendrite arm spacing and size of γ＇ phase particles and maximal microporosity.

关键词： single crystal superallgy. clast dimension high cycle fatigue （HCF） fracture surface

Effects of Ru on Solidification Characteristic and Microstructures of Ni-Based Single Crystal Superalloy

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Journal of Iron and Steel Research(International) 2013年第3期20卷 74-78页

作者： shi Zhen-xue LI Jia-rong liu shi-zhong WANG Xiao-guang YUE Xiao-dai Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

The Ru-free and Ru-containing single crystal superalloys were cast in the directionally solidified furnace,while other alloying element contents were basically kept unchanged.The effects of Ru on the solidification characteristic and microstructures of single crystal superalloy were investigated with differential scanning calorimetry,electron probe micro analyzer,energy-dispersive X-ray spectroscope,scanning electron microscope and transmission electron microscope.The results show that the liquidus temperature of the single crystal superalloy decreases with Ru addition.The primary dendrite arm spacing and volume fraction of γ/γ＇ eutectic both decrease with Ru addition.The sizes of γ＇ phase of dendritic core and interdendritic region have no obvious change with Ru addition.Ru tends to segregate slightly in the dendritic core.The extent of elements segregation decreases with the Ru addition.Ru tends to partition preferentially into the γ matrix.The addition of Ru decreases the partition ratio（the ratio of the γ phases composition over the γ＇ phases composition） of elements Re,W and Mo.

关键词： Ru single crystal superalloy solidification microstructure

Synthesis and Characterization 9-tungstosilicate Complexes with Transition Metal

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Wuhan University Journal of Natural Sciences 1999年第3期4卷 341-344页

作者： Jin, Su-rong liu, shi-zhong Wang, Zheng

The title complexes KaHb[M(SiW9O34)2]?mH2O(M=Ni,Cu,Zn,Fe or Mn) were synthesized by SiW9O34 10? with transition metal respectively and their structure were characterized by mean of elemental analysis, TG-DTA, IR spectra and, UV spectra. In addition, their redox properties in solution were investigated using polarographic and cyclic voltammographic methods. Experimental results indicated that the complexes have Keggin structure and that the heteropolyanions underwent two-step, two-electron tungsten reduction processes.

关键词： heteropoly complexes transition metal synthesis and characterization

Responses of Soil Acid Phosphomonoesterase Activity to Simulated Nitrogen Deposition in Three Forests of Subtropical China

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Pedosphere 2012年第5期22卷 698-706页

作者： HUANG Wen-Juan ZHANG De-Qiang LI Yue-Lin LU XianKai ZHANG Wei HUANG Juan D.OTIENO Z.H.XU liu Ju-Xiu liu shi-zhong CHU Guo-Wei Key laboratory of Vegetation Restoration and Management of Degrade Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650(China) Graduate University of Chinese Academy of Sciences Beijing 100049(China) Department of Plant Ecology University of BayreuthBayreuth 95440(Germany) Environmental Futures Centre&School of Biomoleeular and Physical Sciences Griffith UniversityNathan QLD 4111(Australia)

Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems. A study of responses of soil APA to simulated N deposition was conducted in three succession forests of subtropical China. The three forests include a Masson pine (Pinus massoniana) forest (MPF)-pioneer community, a coniferous and broad-leaved mixed forest (MF)-transition community and a monsoon evergreen broad-leaved forest (MEBF)-climax community. Four N treatments were designed for MEBF: control (without N added), low-N (50 kg N ha-1 year-1), and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1), and only three N treatments (i.e., control, low-N, medium-N) were established for MPF and MF. Results showed that soil APA was highest in MEBF, followed by MPF and MF. Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N treatments. However, soil APA in MEBF exhibited negative responses to high N additions, indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem. Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.

关键词：亚热带森林土壤酸性酯酶活性氮沉降模拟磷酸中国森林生态系统

Ru、Y对铸造高温合金与陶瓷界面反应的影响

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铸造 2024年第6期73卷 810-817页

作者：史振学潘宏涛郝齐赞刘世忠北京航空材料研究院先进高温结构材料重点实验室北京100095

在定向凝固炉中,采用相同的硅基陶瓷型芯,刚玉陶瓷型壳,熔炼工艺和定向凝固工艺制备了四种不同Ru、Y含量的单晶高温合金叶片,研究了组织稳定性提升元素Ru、抗氧化性增强元素Y对合金与陶瓷材料界面反应的影响。研究结果表明,合金中不含Ru... 详细信息

在定向凝固炉中,采用相同的硅基陶瓷型芯,刚玉陶瓷型壳,熔炼工艺和定向凝固工艺制备了四种不同Ru、Y含量的单晶高温合金叶片,研究了组织稳定性提升元素Ru、抗氧化性增强元素Y对合金与陶瓷材料界面反应的影响。研究结果表明,合金中不含Ru、Y时,合金与型壳发生的界面反应主要为物理粘砂作用,未见合金元素与型壳发生明显的化学反应,合金与型芯发生轻微的界面反应,除了物理作用,还发生了Al与SiO2的化学反应。合金中添加Ru,对合金与型壳或型芯的界面反应无影响。合金中添加0.01%Y后,合金与陶瓷型壳或型芯的界面反应稍有增加,但由于其添加量较少,故影响较小。

关键词：陶瓷高温合金界面反应 Ru Y

维普期刊数据库博看期刊

Evidences and implications of vegetation damage from ceramic industrial emission on a rural site in the Pearl River Delta of China

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Journal of Forestry Research 2006年第1期17卷 7-12页

作者： WEN Da-zhi KUANG Yuan wen liu shi-zhong ZHANG De-qiang LU Yao-dong LI Jian-li Institute of Ecology South China Botanical Garden. the Chinese Academy of Sciences Guangzhou 510650 P. R. China Foshan Forestry Research Institute Guangdong 528222 P. R. China Forestry Extension Station of Nanhai District Foshan Guangdong 528222 P. R. China

社区结构特征和植被损坏度我们 reinvestigated 并且在村庄附近在一个森林里分析了，它是长期的暴露了到周围的大气污染应力，在植被上从集中的陶器的工业学习在空中的污染物质排出物的影响。现场甸在多山的土地上在一个 semi-naturalse... 详细信息

社区结构特征和植被损坏度我们 reinvestigated 并且在村庄附近在一个森林里分析了，它是长期的暴露了到周围的大气污染应力，在植被上从集中的陶器的工业学习在空中的污染物质排出物的影响。现场甸在多山的土地上在一个 semi-naturalsecondary 森林里被执行，广东省的 Nanhai 区域，为在有 10 X 的全部的区域的十 quadrates 的树层( 10 m x 10 m )，并且为在有 4 X ( 5 mx5 m )的全部的区域的八 subquadrates 的灌木和植物层。结果证明异国情调的桉树类使突出 and 桉树类 urophylla 在社区上被统治，由本国的树种类， Scheffleraoctophylla 和 Bambusa gibba 列在后面与 26.75， 17.08， 16.27 和 11.50 的重要性价值(I_v ) ，分别地。在所有树种类之中，桉树类使突出 and Pinus massoniana 最严重地与将近百分之百损坏的率被损坏。然而， Bambusa gibba 和 Dalbergia balansae 与 85.1%-68.3% 的损坏的率被伤害桉树类 urophylla， Celtis sinensis， Heliciacochinchinensis， Cinnamomum burmanni 和 Vitex 否定松开揭示中等损害(45%-57.5%) 。Mostof 包括 Schefflera octophylla 的另外的土生土长的种类，荚莲属植物 odoratissimum， Desmoschinensis，少些显示出的等等在污染压力下面伤害了症状。与在树层的种类相比，下层林丛的损坏大部分是更少。这些结果建议注意和担心应该在那些上被给予自从 1970-1980s，曾经是的介绍桉树类种类广泛地在华南的降级的多山的陆地为森林恢复使用了，由于他们的快成长方面。结果也由在类似的弄脏的地点为降级的区域的恢复作为目标植物开发本国的种类表明了潜力和观点，它可以提供科学的底让科学家学习并且理解有污染应力的本国的种类和基于过程的相互作用的功能的方面。

关键词：陶瓷工业空气喷射植被珍珠河大气污染

X-ray-activated Bi^(3+)/Pr^(3+)co-doped LiYGeO_4 phosphor with UV and NIR dual-emissive persistent luminescence

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Journal of Rare Earths 2024年第5期42卷 955-961,I0005页

作者： Xianggui Yin Hongyun zhong Lin liu Junpeng shi Xia Sun Yun Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China

X-ray-activated luminescence materials have broad application prospects in photodynamic therapy of deep tissue.Among them,X-ray-activated persistent luminescence materials(PLMs)exhibiting multiple emission peaks have drawn extensive attention for the ir capacity to achieve a combination of bioimaging and therapeutic functions.Here,we developed a novel PLM,LiYGeO_4:Bi^(3+),Pr^(3+),that simultaneously exhibits UV and NIR dual persistent luminescence(PersL)emissions after irradiation by X-ray.The material can be re peatedly excited by X-ray and emits similar lumine scence intensity every time,which shows good PersL stability.In addition,LiYGeO_4:Bi^(3+),Pr^(3+)exhibits photostimulated PersL properties by stimulation with a red light-emitting diode(LED)or NIR laser after long-term decay.This work provides a new choice of X-ray-excited PLMs with UV and NIR dual emission and the novel phosphor shows promise as a potential candidate for the integration of treatment and diagnosis of deep tumors.

关键词： Co-doping X-ray-activated Dual emissions Persistent luminescence Rare earths

Predictability of the upper ocean heat content in a Community Earth System Model ensemble prediction system

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Acta Oceanologica Sinica 2024年第1期43卷 1-10页

作者： Ting liu Wenxiu zhong State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China School of Atmospheric Sciences Sun Yat-Sen UniversityZhuhai 519082China

Upper ocean heat content(OHC)has been widely recognized as a crucial precursor to high-impact climate variability,especially for that being indispensable to the long-term memory of the ocean.Assessing the predictability of OHC using state-of-the-art climate models is invaluable for improving and advancing climate forecasts.Recently developed retrospective forecast experiments,based on a Community Earth System Model ensemble prediction system,offer a great opportunity to comprehensively explore OHC predictability.Our results indicate that the skill of actual OHC predictions varies across different oceans and diminishes as the lead time of prediction extends.The spatial distribution of the actual prediction skill closely resembles the corresponding persistence skill,indicating that the persistence of OHC serves as the primary predictive signal for its predictability.The decline in actual prediction skill is more pronounced in the Indian and Atlantic oceans than in the Pacific Ocean,particularly within tropical regions.Additionally,notable seasonal variations in the actual prediction skills across different oceans align well with the phase-locking features of OHC variability.The potential predictability of OHC generally surpasses the actual prediction skill at all lead times,highlighting significant room for improvement in current OHC predictions,especially for the North Indian Ocean and the Atlantic Ocean.Achieving such improvements necessitates a collaborative effort to enhance the quality of ocean observations,develop effective data assimilation methods,and reduce model bias.

关键词： ocean heat content prediction skill retrospective forecast experiment