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EMBRITTLEMENT OF A Cr-Mo LOW-ALLOY STEEL DUE TO LOW-TEMPERATURE NEUTRON IRRADIATION

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 20-26页

作者： S.h. Song L. q. Weng Department of Materials Science and Engineering Shenzhen Graduate School HarbinInstitute of Technology Shenzhen 518055 China

Embrittlement of a Cr-Mo2.25CrlMo steel stemming from neutron irradiation at 270℃ is studied by virtue of small punch testing in conjunction with scanning electron microscopy. The ductile-brittle transition temperature determined by the small punch test is much lower than that determined by the standard Charpy test. There is some irradiation-induced embrittlement effect after the steel is irradiated for 46 days with a neutron dose rate of 1.05×10^18dpa/s （displacement per atom per second）.

关键词： irradiation embrittlement segregation low alloy steels pressure vessel

Oxygen and Nitrogen Effects on MC Carbide in K465 Nickel-Base Superalloy

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稀有金属材料与工程 2009年第A03期38卷 13-16页

作者： Wang L N Zheng q Sun X F Guan h R hu Z q Institute of Metals Research Chinese Academy of Sciences Shenyang 110015 China

Effects of oxygen and nitrogen on MC carbide in nickel-base superalloy K465 were investigated, because neither of the two gas elements was found to decide MC carbide morphology monotonically. The morphology of MC carbide under alloy solidified in conventional investment casting condition was observed to transform from script-type to block-type with the total oxygen and nitrogen content (gas content) in samples rising up from 1.2×10-6 mol/g to 2.6×10-6 mol/g. The area fraction and composition of the MC carbide also varied with increase of gas content. however, the morphology of MC carbide kept to be script-type even when gas content was up to 3.4×10-6 mol/g in samples solidified with a much higher cooling rate. These results indicate that effects of gas content on formation of MC carbide can be observed in specimens solidified with low cooling rate, but such changes in MC carbide cannot be found when the cooling rate is high.

关键词：氧碳化物氮含量物理性能碳化物

TiZr-base Bulk Metallic Glass with over 50 mm in Diameter

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Journal of Materials Science & Technology 2010年第6期26卷 481-486页

作者： M. q. Tang h.F. Zhang Z. W. Zhu h.M. Fu A.M. Wang h. Li Z.q. hu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences 72Wenhua Road Shenyang 110016 China

Low-cost TiZr-base bulk metallic glasses （BMGs）（Ti36.1Zr33.2Ni5.8Be24.9）100-xCux （x=5, 7 and g） with a maximum size of over 50 mm in diameter were developed by optimizing the alloy composition. The idea is initiated by selecting a particular microstructure comprising primary β-Ti dendrite and amorphous phase. Afterwards, based on this composition of amorphous phase, a class of TiZr-base bulk metallic glasses was designed step by step to reach the optimum composition range. The glass transition temperature （Tg）, initial crystallization temperature （Tx） and width of supercooled region （AT） of （***33.2Nis.8Be24.9）91Cu9 BMG are 611, 055 and 44 K, respectively. The （Ti36.1Zr33.2Ni5.8Be24.9）91Cu9 BMG exhibits low density of 5.541 g·cm-3 and high compressive fracture strength of 1800 MPa, which promises the potential application as structural materials.

关键词： TiZr-base alloy Bulk metallic glass (BMG) Fracture strength

On Pattern Avoiding Flattened Set Partitions

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Acta Mathematica Sinica,English Series 2015年第12期31卷 1923-1928页

作者： Thomas Y.h.LIU Andy q.ZhANG Department of Foundation Courses Southwest Jiaotong University Center for Combinatorics LPMC-TJKLCNankai University

Let Π = B1/B2/… /Bk be any set partition of[n]= {1,2,...,n} satisfying that entries are increasing in each block and blocks are arranged in increasing order of their first *** Callan defined the flattened Π to be the permutation of[n]obtained by erasing the divers between its blocks,and Callan also enumerated the number of set partitions of[n]whose flattening avoids a single3-letter *** posed the question of counting set partitions of[n]whose flattening avoids a pattern of length *** this paper,we present the number of set partitions of[n]whose flattening avoids one of the patterns：1234,1243,1324,1342,1423,1432,3142 and 4132.

关键词： Set partition pattern avoidance flattened partition

hydrogen Gas Sensor Based on Nanocrystalline SnO_2 Thin Film Grown on Bare Si Substrates

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Nano-Micro Letters 2016年第1期8卷 20-28页

作者： Imad h.Kadhim h.Abu hassan q.N.Abdullah Nano-Optoelectronics Research and Technology Laboratory School of Physics Universiti Sains Malaysia Ministry of Education Physics Department College of Education Tikrit University

In this paper, high.q.ality nanocrystalline SnO_2 thin film was grown on bare Si(100) substrates by a sol–gel method. A metal–semiconductor–metal gas sensor was fabricated using nanocrystalline SnO_2 thin film and palladium(Pd)metal. The contact between Pd and nanocrystalline SnO_2 film is tunable. Ohmic barrier contact was formed without addition of glycerin, while Schottky contact formed by adding glycerin. Two kinds of sensor devices with Schottky contact were fabricated(Device 1: 8 h, 500 °C; Device 2: 10 h, 400 °C). The room temperature sensitivity for hydrogen(h_2) was120 and 95 % in 1000 ppm h_2, and the low power consumption was 65 and 86 l W for two devices, respectively. At higher temperature of 125 °C, the sensitivity was increased to 195 and 160 %, respectively. The sensing measurements were repeatable at various temperatures(room temperature, 75, 125 °C) for over 50 min. It was found that Device 1 has better sensitivity than Device 2 due to its better crystallinity. These findings indicate that the sensors fabricated on bare Si by adding glycerin to the sol solution have strong ability to detect h_2 gas under different concentrations and temperatures.

关键词： SnO2 Glycerin Sol–gel Schottky contact hydrogen sensor

Ultra-short Term Wind Speed Prediction Using Mathematical Morphology Decomposition and Long Short-term Memory

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CSEE Journal of Power and Energy Systems 2020年第4期6卷 890-900页

作者： Mengshi Li Zhiyuan Zhang Tianyao Ji q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

This paper proposes a new model,which consists of a mathematical morphology(MM)decomposer and two long short term memory(LSTM)networks,to perform ultra-short term wind speed *** MM decomposer is developed in order to improve the forecast accuracy,which separates the wind speed into two parts:a stationary long-term baseline and a nonstationary short-term ***,two LSTM networks are implemented to forecast the baseline and residue,***,this paper makes an integrated forecast that takes into account multiple climate factors,such as temperature and air *** baseline,temperature and air pressure are used as the inputs of baseline network for training and prediction,and the baseline,residue,temperature and air pressure are used as the inputs of residue network for training and *** performance of the proposed model has been validated using data collected from the Australian Meteorological Station,which is compared with least squares-support vector machine(LS-SVM),back-propagation artificial neural network(BPNN),LSTM,MM-LS-SVM,and *** results demonstrate that the proposed model is more suitable to solve non-stationary time-series forecast,and achieves higher accuracy than the other models under various conditions.

关键词： Deep learning long short-term memory network mathematical morphology wind speed forecast

重型燃气轮机用定向凝固UGTC47合金近服役条件下的显微组织演化

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维普期刊数据库

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材料热处理学报 2025年第2期46卷 152-163页

作者：李家兴陆民刚束国刚杨德宇申茹茹郑为为北京科技大学新金属材料国家重点实验室北京100083 中国联合重型燃气轮机技术有限公司北京100016

重型燃气轮机透平叶片长时服役过程中受温度和应力作用,将不可避免发生显微组织损伤。以国产定向凝固UGTC47合金为研究对象,研究其在850~950℃近服役温度范围内热暴露及热力耦合模拟1000、3000和5000 h后的显微组织演化。结果表明:经标... 详细信息

重型燃气轮机透平叶片长时服役过程中受温度和应力作用,将不可避免发生显微组织损伤。以国产定向凝固UGTC47合金为研究对象,研究其在850~950℃近服役温度范围内热暴露及热力耦合模拟1000、3000和5000 h后的显微组织演化。结果表明:经标准热处理的UGTC47合金在850~950℃热暴露及热力耦合模拟后,枝晶干γ′相的退化速度大于枝晶间区域的γ′相,枝晶干γ′相体积分数在退化初期就下降至60%左右;应力会促进γ′相体积分数趋于平衡状态,但在850、900和950℃热力耦合模拟5000 h下无显著差别,仍保持55%左右。γ′相尺寸基本符合LSW理论的生长模型。随着应力的增加和时间的延长,γ′相筏排化程度逐渐增大至0.6左右后趋于稳定,时间继续延长,甚至有所降低;γ相通道宽度随温度和应力增加呈线性增大趋势。

关键词：定向凝固UGTC47合金重型燃气轮机近服役温度热力耦合显微组织

Influence of Zn Doping on Novel Cathode Material LiFePO_4

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复旦学报（自然科学版） 2005年第5期44卷 877-878页

作者： h. Liu C. Li q. Cao h.P. Zhang Y.P. Wu h.q. Wu Department of Chemistry ＆ Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan University Shanghai 200433 China

The novel cathode material LiFePO4 for lithium ion battery is considered as the substitute of LiCoO2 because of its high theoretical capacity, environmental benignancy and inexpensive cost[1,2]. But it is restricted by its low conductivity, the traditional ways to improve are carbon coating[3,4] and heteroatom doping[5-7].In this paper, we introduced the Zn as heteroatom and investigated the improvement by Zn doping.

关键词： LiFePO4 锂电池电解液阴极电化学

Real-time Dispatchable Region of Renewable Generation Constrained by Reactive Power and Voltage Profiles in AC Power Networks

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CSEE Journal of Power and Energy Systems 2020年第3期6卷 528-536页

作者： Yanqi Liu Zhigang Li q.h.Wu haibo Zhang School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

A large amount of renewable energy generation(REG)has been integrated into power systems,challenging the operational security of power *** a real-time dispatch,system operators need to estimate the ability of the power network to accommodate REG with a limited reserve *** real-time dispatchable region(RTDR)is defined as the largest range of a power injection that the power network can accommodate in a certain dispatch interval for a given dispatch base ***-of-the-art research on the RTDR adopts a DC power flow model regardless of the voltage profiles and reactive power,which can overlook potentially insecure operational states of the *** address this issue,this paper proposes an AC power flow based RTDR model simultaneously considering the reactive power and voltage profiles *** nonlinear constraints in our model are approximated using a linear power flow model together with a polytope approximation technique for quadratic *** adaptive constraint generation algorithm is used to calculate the *** results using the IEEE 5-bus and 30-bus systems illustrate the advantages of the proposed model.

关键词： Dispatchable region linearization renewable energy generation reactive power