|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 湖泊现代沉积物碳环境记录研究显示文摘通过对云南程海现代沉积物的精细采样和分析,研究了湖泊沉积物中有机碳与无机碳含量阶段性的正相关和负相关变化.结果表明,温度及其引起的相关变化是控制沉积物无机碳含量、碳酸盐δ13C和有机碳含量变化关系的主要因素.当温度及其引起的光合作用强度变化对湖泊自生碳酸钙沉淀起主导作用时,沉积物有机碳含量与无机碳含量及碳酸盐δ13C呈正相关变化;当温度及其引起的蒸发速率等其他物理化学因素变化对湖泊自生碳酸钙沉淀起主导作用时,沉积物有机碳含量与无机碳含量及碳酸盐δ13C呈负相关变化.程海沉积物无机碳含量和碳酸盐δ13C是湖区气候冷暖变化的良好代用指标. | 陈敬安 万国江 汪福顺 黄荣贵 张峰 D.D.Zhang R.Schmidt | 2002 | 中国科学(D辑)2002，32，1： | 79 |
| 2 | Environmental records of carbon in recent lake sediments显示文摘Based on careful sampling and accurate analysis of recent sediments in Lake Chenghai, this paper discusses the staggered positive/negative correlation between organic carbon (OC) concentration and inorganic carbon (IC) concentration. The result indicates that temperature change, and its induced relative changes are the main factors affecting the relationship between IC concentration, δ13C of carbonate and OC concentration. When temperature and its induced photosynthesis strength change control autochthonous calcite precipitation, OC concentration is positively correlated with IC concentration and δ13C of carbonate. When temperature and its induced physical/chemical changes dominate, OC concentration displays negative correlation with IC concentration and δ13C of carbonate. IC concentration and δ13C of carbonate in sediments of Lake Chenghai are good proxies for climatic warm/cold changes. | 陈敬安 万国江 汪福顺 张峰 黄荣贵 D.D.Zhang R.Schmidt | 2002 | Science China Earth Sciences2002，45，10： | 6 |
| 3 | A strong and ductile NiCoCr-based medium-entropy alloy strengthened by coherent nanoparticles with superb thermal-stability显示文摘In this work,we designed a novel NiCoCr-based medium-entropy alloy(MEA)strengthened by coher-ent L12-nanoparticles,i.e.,(NiCoCr)92 Al 6 Ta 2(at.%).The strengthening and deformation mechanisms of the material and the coarsening kinetics of the coherent precipitates were systematically investigated.The results indicated that giant precipitation hardening and its synergy with other strengthening contributors confer on the aged material a yield strength as high as 1.0 GPa.Moreover,a unique particle-features-dependent plasticity mechanism was revealed in this alloy.That is,the alloy with a lower volume frac-tion,denser distribution,and finer particles mainly deformed by dislocation planar slip,otherwise,stack-faults-mediated plasticity was favored,rationalized by the cooperative/competitive effect of stack-fault energy,spatial confinement,and applied stress.Furthermore,the coarsening behavior of precipitate fol-lowed a modified Lifshitz-Slyozov-Wagner(LSW)model,and the nanoparticles displayed remarkably su-perior thermal stability compared to most traditional superalloys and reported multicomponent alloys.The superb coarsening resistance of precipitate originated from the coupled effect of intrinsic sluggish diffusion in multi-principal alloys and the dual-roles of Ta species as a precipitate stabilizer.This work provides a new pathway to develop strong-yet-ductile multicomponent alloys as promising candidates for high-temperature applications. | D.D.Zhang J.Kuang H.Xue J.Y.Zhang G.Liu J.Sun | 2023 | Journal of Materials Science & Technology2023，，1： | 2 |
| 4 | Achieving excellent strength-ductility synergy in twinned NiCoCr medium-entropy alloy via Al/Ta co-doping显示文摘Alloying is an effective strategy to tailor microstructure and mechanical properties of metallic materials to overcome the strength-ductility trade-off dilemma.In this work,we combined a novel alloy design principle,i.e.harvesting pronounced solid solution hardening(SSH)based on the misfit volumes engineering,and simultaneously,architecting the ductile matrix based on the valence electron concentrations(VEC)criterion,to fulfill an excellent strength-ductility synergy for the newly emerging high/medium-entropy alloys(HEAs/MEAs).Based on this strategy,Al/Ta co-doping within NiCoCr MEA leads to an efficient synthetic approach,that is minor Al/Ta co-doping not only renders significantly enhanced strength with notable SSH effect and ultrahigh strain-hardening capability,but also sharply refines grains and induces abnormal twinning behaviors of(NiCoCr)_(92)Al_(6)Ta_(2) MEA.Compared with the partially twinned NiCoCr MEA,the yield strength(σy)and ultimate tensile strength(σUTS)of fully twinned Al/Ta-containing MEA were increased by~102%to~600 MPa and~35%to~1000 MPa,respectively,along with good ductility beyond 50%.Different from the NiCoCr MEA with deformation twins(DTs)/stacking faults(SFs)dominated plasticity,the extraordinary strain-hardening capability of the solute-hardened(NiCoCr)_(92)Al_(6)Ta_(2) MEA,deactivated deformation twinning,originates from the high density of dislocation walls,microbands and abundance of SFs.The abnormal twinning behaviors,i.e.,prevalence of annealing twins(ATs)but absence of DTs in(NiCoCr)_(92)Al_(6)Ta_(2) MEA,are explained in terms of the relaxation of grain boundaries(for ATs)and the twinning mechanism transition(for DTs),respectively. | D.D.Zhang H.Wang J.Y.Zhang H.Xue G.Liu J.Sun | 2021 | Journal of Materials Science & Technology2021，，28： | 1 |
| 5 | Unusual He-ion irradiation strengthening and inverse layer thickness-dependent strain rate sensitivity in transformable high-entropy alloy/metal nanolaminates:A comparison of Fe_(50)Mn_(30)Co_(10)Cr_(10)/Cu vs Fe_(50)Mn_(30)Co_(10)Ni_(10)/Cu显示文摘In this work,we prepare transformable HEA/Cu nanolaminates(NLs)with equal individual layer thick-ness(h)by the magnetron sputtering technique,i.e.,Fe_(50)Mn_(30)Co_(10)Cr_(10)/Cu and Fe_(50)Mn_(30)Co_(10)Ni_(10)/Cu,and comparatively study He-ion irradiation effects on their microstructure and mechanical properties.It ap-pears that the as-deposited HEA/Cu NLs manifest two size h-dependent hardness regimes(i.e.,increased hardness at small h and hardness plateau at large h),while the He-implanted ones exhibit monotonically increased hardness.Contrary to the fashion that smaller h renders less irradiation hardening in bimetal NLs,the Fe_(50)Mn_(30)Co_(10)Cr_(10)/Cu NLs manifest the trend that smaller h leads to greater irradiation hard-ening.By contrast,the Fe_(50)Mn_(30)Co_(10)Ni_(10)/Cu NLs exhibit the maximum irradiation hardening at a critical h=50 nm.Below this critical size,smaller h results in lower radiation hardening(similar to bimetal NLs),while above this size,smaller h results in greater radiation hardening(similar to Fe_(50)Mn_(30)Co_(10)Cr_(10)/Cu NLs).Moreover,these transformable HEA/Cu NLs display inverse h-dependent strain rate sensitivity(SRS m)before and after He-ion irradiation.Nevertheless,compared with as-deposited samples,the irradi-ated Fe_(50)Mn_(30)Co_(10)Cr_(10)/Cu NLs display reduced SRS,while the irradiated Fe_(50)Mn_(30)Co_(10)Ni_(10)/Cu NLs dis-play enhanced SRS.Such unusual size-dependent irradiation strengthening and inverse h effect on SRS in irradiated samples were rationalized by considering the blocking effects of He bubbles on dislocation nucleation and motion,i.e.,dislocations shearing or bypassing He bubbles. | Y.F.Zhao H.H.Chen D.D.Zhang J.Y.Zhang Y.Q.Wang K.Wu G.Liu J.Sun | 2022 | Journal of Materials Science & Technology2022，，21： | 1 |
| 6 | Subpulse Drifting of PSR J1110–5637显示文摘We report a detailed study of polarization characteristics and subpulse drifting in PSR J1110-5637 with the observations of the Parkes 64 m radio telescope at 1369 MHz.The observations revealed that the trailing component of the pulse profile has obvious subpulse drifting,while the leading component has no subpulse drifting.Using the two-dimensional fluctuation spectrum(2DFS),we detected three distinct emission modes in the trailing component(modes A,B and C).The emission in mode A is chaotic and indistinguishable,while modes B and C have obvious subpulse drifting.The vertical modulation periods P3of modes B and C are around the mean values of 12 P and 8 P,respectively.The subpulse drifting of PSR J1110-5637 will expand the pulsar sample with multiple subpulse drifting rates,and this will help future systematic studies on the physical origin of the subpulse drifting phenomenon. | S.J.Dang L.H.Shang L.Lin Q.J.Zhi R.S.Zhao C.B.Wu Z.Y.You A.J.Dong J.T.Bai X.Xu D.D.Zhang H.Yang Q.W.Lin | 2022 | Research in Astronomy and Astrophysics2022，22，6： | 0 |
| 7 | Designing hetero-structured ultra-strong and ductile Zr-2.5Nb alloys:Utilizing the grain size-dependent martensite transformation during quenching显示文摘To further improve the service performance of Zr-2.5Nb alloy worked as pressure tubes in pressurized heavy water reactors,more investigation about the microstructure and thermomechanical processing route of Zr-2.5Nb alloy need to be conducted.In this work,a hetero-structured Zr-2.5Nb alloy was prepared by applying a novel technique.Microstructure analysis reveals that the alloy exhibits a grain sizedependent martensite substructure transition during post-rolling quenching.The hetero-structure consists of equiaxed primaryαgrains and the lamellae groups containing both parallelα’dislocation martensite andα’twin martensite.Compared with the previously reported Zr-Nb alloys,the present Zr-2.5Nb alloys manifest the highest yield strength(∼710 MPa),together with a high ultimate tensile strength(∼844 MPa)and good ductility(∼17.1%).The enhanced mechanical properties are found to arise from the properly controlled fraction/size of the two types of martensite,which not only significantly strengthens the alloy but also contributes to a stronger strain hardening.A model based on the grain-size-dependent critical resolved shear stress for dislocation slip and twinning has been proposed to explain theα’martensite substructures transition at a critical grain size dc=3.3μm.Below this size,the critical resolved shear stress(CRSS)for twinning is higher than that for theslip.Thus,theα’dislocation martensite is more favorable to form.Otherwise,theα’twin martensite would exhibit a high activity.The present work indicates that making use of the grain size-dependent martensite transformation to tailor the heterostructure in Zr alloys is an effective strategy to overcome the strength–ductility trade-off in the material. | S.Y.Liu J.Y.Zhang J.Kuang X.Y.Bao D.D.Zhang C.L.Zhang J.K.Yang G.Liu J.Sun | 2022 | Journal of Materials Science & Technology2022，，30： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员