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HIGH-TEMPERATURE AC MAGNETIC PROPERTIES OF NANOCRy.TALLINE FINEMET ALLOy. WITH Co ADDITION

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Acta Metallurgica Sinica(English Letters) 2007年第5期20卷 327-333页

作者： y.H. Ding x. Liu S.S. Zhao y. Long R.C. y. y.Q. chang F.R. Wan School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China College of Science Tianjin University of Technology Tianjin 300191 China

High-temperature AC magnetic properties for （Fe0.5Co0.5）73.5Cu1Nb3Si13.5B9 alloy.annealed at various temperatures have been investigated using an impedance analy.er. Annealing temperature Ta has obvious effects on high-temperature AC magnetic properties of the alloy. The Hopkinson peak appears only.in the amorphous alloy.when Ta≤703K. As Ta increases above 733K, the real part of the complex.initial permeability.μi′descends gradually. μi′decreases more slowly.with temperature in the high temperature range. The high-temperature （about 750K） AC initial permeability.for the alloy.annealed at Ta= 763K has been found to maintain a stable high value of 950 up to a frequency.of- 1 × 10^5Hz. Partial substitution of Co for Fe in the F73.5Cu1Nb3Si13.5B9 alloy.leads to an increase of around 110K of the Curie temperature of the amorphous phase, much higher than Ge-containing Finemet alloy.

关键词： high temperature nanocry.talline permeability.spectra

Sensitivity.to Acidification of Forest Soils in Two Watersheds with Contrasting Hy.rological Regimes in the Oil Sands Region of Alberta

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Pedosphere 2007年第6期17卷 747-757页

作者： y. S. OK S. x. chang y. S. FENG Department of Renewable Resources University of Alberta Edmonton AB T6G 2E3 （Canada）. Department of Biological Environment Kangwon National University Chuncheon 200-701 （Korea）

Input of large amounts of N and S compounds into forest ecosy.tems through atmospheric deposition is a significant risk for soil acidification in the oil sands region of *** evaluated the sensitivity.of forest soils to acidification in two watersheds(Lake 287 and Lake 185)with contrasting hy.rological regimes as a part of a larger project assessing the role of N and S cy.ling in soil acidification in forest *** six.forest soil samples were collected from the two watersheds by.horizon from 10 monitoring plots dominated by.either jack pine(Pinus banksiana)or aspen(Populus tremuloides).Soils in the two watersheds were ex.remely.to moderately.acidic with pH(CaCl_2)ranging from 2.83 to *** acid-base chemistry.variables such as pH,base saturation,Al saturation,and acid-buffering capacity.measured using the acetic acid equilibrium procedure indicated that soils in Lake 287 were more acidified than those in Lake 185. Acid-buffering capacity.decreased in the order of forest floor>subsurface mineral soil>surface mineral *** most dramatic differences in percent Ca and Al saturations between the two watersheds were found in the surface mineral soil *** Ca and Al saturation in the surface mineral soil in Lake 287 were 15% and 70%,respectively.the percent Ca saturation value fell within a critical range proposed in the literature that indicates soil *** results suggest that the soils in the two watersheds have low acid buffering capacity.and would be sensitive to increased acidic deposition in the region.

关键词： acid-buffering capacity Al saturation base saturation pH soil acidification

Influence of Co Content on Raman and Photoluminescence Spectra of Co Doped ZnO Nanowires

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Journal of Materials Science & Technology 2012年第4期28卷 313-316页

作者： y.Q. chang P.W. Wang S.L. Ni y. Long x.D. Li School of Materials Science anti Engineering University of Science and Technology Beijing Beijing 100083 China Department of Phy.ics National Key Laboratory of Mesoscopic Physics Peking University Beijing 100871 China

Co doped ZnO nanowires with different Co contents have been fabricated by.a chemical vapor deposition method. x.ray.diffraction results show that all the samples are of single phase and cry.tallize in wurtzite ZnO structure. The lattice parameter a increases with increasing Co content, while the parameter c has no obvious change with increasing Co. Raman spectra show that the nonpolar E2（High） mode becomes broad and weak with the doping of Co, which indicates that the incorporation of Co causes structural disorder in the cry.talline columnar ZnO lattice. The photolurninescence spectra ex.ibit that the position of the ultraviolet emission shifts to short wavelength and the intensity.decreases with increasing Co. The green emission is affected by.two contrary.factors. It is increased by.the introduced defects, but suppressed by.the interaction between Co doping and native defects and the later affects it more significantly.

关键词： Co doped ZnO nanowires Raman Photoluminescence Single phase

Ex.erimental Hamiltonian Learning of an 11-Qubit Solid-State Quantum Spin Register

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Chinese Phy.ics Letters 2019年第10期36卷 11-16页

作者： P.-y.Hou L.He F.Wang x.-Z.Huang W.-G.Zhang x.-L.Ouy.ng x.Wang W.-Q.Lian x.-y.chang L.-M.Duan Center for Quantum Information Institute for Interdisciplinary Information SciencesTsinghua UniversityBeijing 100084

Learning the Hamiltonian of a quantum sy.tem is indispensable for prediction of the sy.tem dy.amics and realization of high fidelity.quantum ***,it is a significant challenge to efficiently.characterize the Hamiltonian which has a Hilbert space dimension ex.onentially.growing with the sy.tem ***,we develop and implement an adaptive method to learn the effective Hamiltonian of an 11-qubit quantum sy.tem consisting of one electron spin and ten nuclear spins associated with a single nitrogen-vacancy.center in a *** validate the estimated Hamiltonian by.designing universal quantum gates based on the learnt Hamiltonian and implementing these gates in the *** ex.erimental result demonstrates a well-characterized 11-qubit quantum spin register with the ability.to test quantum algorithms,and shows our Hamiltonian learning method as a useful tool for characterizing the Hamiltonian of the nodes in a quantum network with solid-state spin qubits.

关键词： Hamiltonian quantum sy.tem

Proton therapy.in clinical practice

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Chinese Journal of Cancer 2011年第5期30卷 315-326页

作者： Hui Liu Joe y. chang Sun y.t-sen University.Cancer Center Guangzhou Guangdong 510060 P. R. China Radiation Oncology.Department University of Texas MD Anderson Cancer Center Houston TX 77030 USA

Radiation dose escalation and acceleration improves local control but also increases *** radiation is an emerging therapy.for localized cancers that is being sought with increasing frequency.by.*** with photon therapy.proton therapy.spares more critical structures due to its unique *** phy.ical properties of a proton beam make it ideal for clinical *** modulating the Bragg peak of protons in energy.and time,a conformal radiation dose with or without intensity.modulation can be delivered to the target while sparing the surrounding normal ***,proton therapy.is ideal when organ preservation is a ***,protons are more sensitive to organ motion and anatomy.changes compared with *** this article,we review practical issues of proton therapy.describe its image-guided treatment planning and delivery.discuss clinical outcome for cancer patients,and suggest challenges and the future development of proton therapy.

关键词：质子束临床实践治疗 Bragg峰辐射剂量物理特性局部控制癌症病人

New approaches to water purification for resource- constrained settings： Production of activated biochar by.chemical activation with diammonium hy.rogenphosphate

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Frontiers of Chemical Science and Engineering 2018年第1期12卷 194-208页

作者： Mohit Nahata chang y. Seo Pradeep Krishnakumar Johannes Schwank Department of Chemical Engineering University of Michigan-Ann Arbor Ann Arbor MI 48109 USA

A significant portion of the world＇s population does not have access to safe drinking water. This problem is most acute in remote, resource-constrained rural settings in developing countries. Water filtration using activated carbon is one of the important steps in treating con- taminated water. Lignocellulosic biomass is generally.available in abundance in such locations, such as the African rain forests. Our work is focused on developing a simple method to sy.thesize activated biochar from locally.available materials. The preparation of activated biochar with diammonium hy.rogenphosphate （DAP） as the activating agent is ex.lored under N2 flow and air. The study. carried out with cellulose as a model biomass, provides some insight into the interaction between DAP and biomass, as well as the char forming mechanism. Various characterization techniques such as N2 phy.isorption, x.ray.photoelectron spectroscopy. scanning electron microscopy. transmission electron microscopy.and Raman spectroscopy.are utilized to compare the properties between biochar formed under nitrogen and partial ox.dative conditions. At a temperature of 450 ℃, the loading of DAP over cellulose is sy.tematically.varied, and its effect on activation is ex.mined. The activated biochar samples are predominantly.microporous in the range of concentrations studied. The interaction of DAP with cellulose is investigated and the nature of bonding of the heteroatoms to the carbonaceous matrix.is elucidated. The results indicate that the quality.of biochar prepared under partial ox.dation condition is comparable to that ofbiochar prepared under nitrogen, leading to the possibility.of an activated biochar production scheme on a small scale in resource-constrained settings.

关键词： cellulose DAP activation heteroatom,microporous

Development of materials design tool and its application in Pb-free micro-solders in electronic package

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Science China(Technological Sciences) 2010年第6期53卷 1495-1500页

作者： OHNUMA Ikuo KAINUMA Ry.suke ISHIDA Kiy.hito chang Austin y. Department of Materials Science Graduate School of EngineeringTohoku UniversitySendai 980-8579Japan Department of Materials Science and Engineering University of WisconsinMadisonUSA

A materials design tool for developing Pb-free soldering alloy. in electronic package was developed based on comprehensive ex.erimental data of phase equilibria and thermody.amic properties data accumulated with the CALPHAD (calculation of phase diagrams) method and contains 10 elements,namely.Ag,Au,Bi,Cu,In,Ni,Sb,Sn,Zn and *** can handle the calculation of phase diagrams in all combinations of these elements and all composition *** addition,based on this tool,the liquidus,solidus,phase fractions and constitutions,equilibrium and non-equilibrium solidification behavior,surface tension and viscosity.of liquid,diffusion reactions and microstructural evolution,*** be *** ex.mples of the calculation and application of this tool are *** design tool is ex.ected to be a powerful tool for the development of Pb-free solders,as well as for promoting the understanding of the interfacial phenomena between Cu substrate and Pb-free solders in electronic packaging technology.

关键词： Pb-free solders thermody.amic database calculation of phase diagram phase field method interfacial reaction

循环加载与卸围压组合扰动下红砂岩损伤破裂与渗透特性

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岩土工程学报 2025年第1期47卷 48-56页

作者：姚玮俞缙周先齐常方强常旭厦门理工学院土木工程与建筑学院福建厦门361024 华侨大学福建省隧道与城市地下空间工程技术研究中心福建厦门361021

为探究深地工程开挖诱导岩体损伤破裂及渗透性演化规律,开展了同步测定波速与渗透率的循环加载与卸围压组合扰动三轴试验,研究了不同条件下红砂岩的损伤与渗透性演化规律。结果表明:①岩石在不同组合扰动阶段具有不同的应力应变曲线形态... 详细信息

为探究深地工程开挖诱导岩体损伤破裂及渗透性演化规律,开展了同步测定波速与渗透率的循环加载与卸围压组合扰动三轴试验,研究了不同条件下红砂岩的损伤与渗透性演化规律。结果表明:①岩石在不同组合扰动阶段具有不同的应力应变曲线形态,其末端形态取决于在何种扰动阶段破坏,初始应力比为决定组合扰动诱发岩石破坏难易的主要因素;②总峰值轴向应变随初始应力比增大而增大,其中组合扰动轴向应变占比始终较低,总峰值体积应变绝对值随初始应力比增大而先增大后减小,其中组合扰动体积应变占比较高;③在初始加载阶段,波速增大,渗透率降低,在组合扰动阶段,波速下降,渗透率增加,且损伤与体积应变近似呈线性关系,损伤与渗透率随扰动次数增加均呈先慢后快的增长趋势,且拐点分别近似在一条直线上;④岩石在组合扰动卸围压阶段破坏为单剪切破坏模式,在组合扰动循环加载阶段破坏为共轭剪切破坏模式;⑤双高(高初始应力比与高初始围压)条件将显著加剧岩体开挖失稳破坏风险。

关键词：深地工程组合扰动力学特性损伤渗透性

INFLUENCE OF Ge ON THE ANTIFERROMAGNETIC TRANSITION AND γ→ε MARTENSITIC TRANSFORMATION OF Fe-24Mn ALLOy.

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Acta Metallurgica Sinica(English Letters) 2002年第6期15卷 517-524页

作者： B. Zhang, x. Lu Z.x. Qin, H.B. chang and x.y. RuanDepartment of Plastic Deforming, Shanghai Jiaotong University. Shanghai 200030, ChinaDepartment of Materials Science & Engineering, Dalian Railway.Institute, Dalian 116028, China Dept. of Plastic Deforming Shanghai Jiaotong Univ. Shanghai 200030 China Dept. of Mat. Sci. and Eng. Dalian Railway Inst. Dalian 116028 China

The aims of the work were to study.the effect of Ge (0-6wt. %) on the paramagnetic-antiferromagnetic transition and martensitic transformation of Fe-Mn alloy.using the susceptibility. micro structure ex.mination, x.ray.diffraction (x.D) and latticeparameter measurement. Ge lowers the Néel temperature, TN, and enhances the magnetic susceptibility.x. changing the Pauli paramagnetism above TN to paramagnetismstate obey.ng the Curie Weiss law, which is essentially.similar to that of γ-Fe-Mnalloy. containing Al or Si; Ge depresses γ-ε martensitic transformation, whichattribute to Ge increasing the stacking fault energy. Moreover, Ge increases the lattice parameter of γ phase, and low content Ge increases the lattice parameter of γphase more than that of high Ge content. Comparing Ge(4s24p2) with Si(3s23p2) and Al(3s2 3p1), which have the same outer-shell of electron structures, we found that their effects on the martensitic transformation of Fe-Mn alloy.are completely.different. The result suggests the outer-shell of electron is not the main factor of governing the Ms temperature of Fe-Mn alloy.although it is essential in the alloy.s antiferromagnetic transition. The relation among the Ms temperature, stacking fault energy.and lattice parameter of austenite, has been discussed in brief.

关键词： antiferromagnetic transition martensitic transformation lattice parameter