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Earthquake Engineering and Engineering Vibration 2015年第2期14卷 217-228页

作者： Teng-To Yu Chi-Shin Wu Youg-Sin cheng Department of Resources Engineering Cheng Kung University (NCKU)

Temporal changes in site effects are obtained using the HVSR(horizontal-to-vertical spectral ratio) method and strong motion records after the M w 7.6 Chi-Chi earthquake, Taiwan. Seismic data recorded between 1995 and 2010 are used, comprising 3,708 data from 15 stations adjacent to the Chelungpu fault. Temporal fl uctuations are determined by analyzing the site effect variation using a time–frequency variation(TFV) diagram based on these seismic data. Stations adjacent to the fault show signifi cant disturbances in the resonance frequency at 16–26 Hz. Station TCU129 shows a 40% drop in fundamental frequency after the main shock, and a gradual return to the original state over nine years. For stations located farther from the fault zone, sudden changes in tectonic stress play a dominant role in temporal changes to the HVSR. An impact analysis of the directional factor confi rms our fi nding that the proximity of the fault to seismic stations has the most infl uence on data.

关键词： Chi-Chi earthquake horizontal-to-vertical spectral

Modification strategies on nickel-based electrocatalysts for energyefficient anodic reactions

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Nano Research 2025年第1期18卷 50-75页

作者： Jingwen Yu Yunliang Liu Naiyun Liu Yaxi Li Yuanyuan cheng Peng Cao Yixian Liu Xinya Yuan Xinyue Zhang Haitao Li Institute for Energy Research School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013China

Electrocatalytic chemical oxidation(ECO)is an energy-efficient anodic reaction alternative to the oxygen evolution reaction(OER).ECO lowers the reaction potential and yields higher-value fine chemicals at the *** catalyst material plays a crucial role in influencing and determining ECO *** catalyst performance encompasses aspects such as activity,stability,selectivity and *** electrocatalysts have garnered significant attention for their exceptional performance and widespread use in ECO *** modifying nickel-based electrocatalysts,the formation of NiOOH active centers can be *** such as adjusting size and morphology,doping,introducing defects and constructing heterojunctions are advantageous for enhancing *** the rapid advancements in related research fields,it is imperative to comprehend the mechanisms of nickel-based electrocatalysts in ECO and develop innovative *** article provides an overview of the modification strategies of nickel-based electrocatalysts,as well as their applications and mechanisms in ECO.

关键词： anodic reactions electrocatalytic chemical oxidation nickel-based electrocatalysts NiOOH modification strategies

不同容量风电场对连接处的电网影响及其性能分析(英文)

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控制理论与应用 2008年第2期25卷 377-382页

作者：董萍郑家伟郭攀香港理工大学电机工程系中国香港江西科技师范大学数学与计算机科学系江西南昌330013

风电场可以同输变电线路相连接,由于风力发电的随机性,风电很有可能给连接处的电网带来谐波污染、电压波动及闪变问题;也会给发电和运行调度计划的制定带来很多困难.对接有风电场的电力系统,重新评估系统的发电可靠性,分析风电容量可信... 详细信息

风电场可以同输变电线路相连接,由于风力发电的随机性,风电很有可能给连接处的电网带来谐波污染、电压波动及闪变问题;也会给发电和运行调度计划的制定带来很多困难.对接有风电场的电力系统,重新评估系统的发电可靠性,分析风电容量可信度;研究新的无功调度及电压控制策略以保证风电场和整个系统的电压水平和无功平衡,及对孤立系统的稳定性影响等对于系统的工程师来说非常重要.本文分析了各种不同容量的风电场对电网的影响并给出模型以及相关结果.

关键词：风电场容量电力透入率可靠性

QUANTITATIVE ANALYSIS OF VERY WEAK ACID AND BASE BY pH-FIXED TITRATION METHOD

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Chinese Chemical Letters 1990年第1期1卷 81-84页

作者： Gang XU Ping WEI Yu cheng XIE Xing dong YU(Jiangsu Institute of Chemical Technology,Changzhou,213016)

pH-fixed titration method for the determination of weak acids and bases has been studied in this *** is not necessary to know the ionization constant of weak acid or base and the concentration of titrant. This method had been applied to determine phenol,4-aminoantipyrine and glycine,whose ionization constants range from 10^(-10)to 10^(-12).The results were satisfactory.

关键词： AATP acid QUANTITATIVE ANALYSIS OF VERY WEAK ACID AND BASE BY pH-FIXED TITRATION METHOD ACID pH

Synergistic Effect between Nano-ceramic Lubricating Additives and Electroless Deposited Ni-W-P Coating

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 114-120页

作者： CHEN Min cheng Wushan ZHAO Zuxin HUANG Xiaobo College of Mechanical Engineering Shanghai University of Engineering Science School of Mechanical and Power Engineering East China University of Science and Technology

The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating （with heat treatment and in oil with nano-ceramic additives） has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.

关键词： Ni-W-P alloy coating nano-ceramic lubricating additives friction-wear mechanism synergistic effect

热处理对GH4169合金组织及650℃下低周疲劳性能的影响

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材料热处理学报 2016年第4期37卷 69-75页

作者：丁天胜张显程涂善东轩福贞华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室上海200237

采用两种不同热处理工艺对GH4169合金进行处理,观察并研究了合金的显微组织变化以及在5个应变幅(1.2%、1.0%、0.8%、0.6%和0.5%)和650℃条件下δ相对合金低周疲劳性能的影响。结果表明:随着900℃保温时间的延长,合金δ相的析出量增加。... 详细信息

采用两种不同热处理工艺对GH4169合金进行处理,观察并研究了合金的显微组织变化以及在5个应变幅(1.2%、1.0%、0.8%、0.6%和0.5%)和650℃条件下δ相对合金低周疲劳性能的影响。结果表明:随着900℃保温时间的延长,合金δ相的析出量增加。合金在高应变幅(Δεt/2≥0.6%)下的疲劳寿命基本不受δ相含量变化的影响;而在较小应变幅下(Δεt/2=0.5%)的疲劳寿命则具有一定的分散性,并随着δ相含量的增加而增加;与此同时,合金的塑性应变-寿命曲线在常温下具有的双线性特征在650℃高温下却不再具有,而且疲劳断口在相同应变幅下呈现出相似的形貌,裂纹源数量也随着应变幅的增加而增加。

关键词：热处理 GH4169合金 δ相高温低周疲劳

High harmonic exploring on different materials in dynamic atomic force microscopy

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Science China(Technological Sciences) 2018年第3期61卷 446-452页

作者： ZHENG ZhiYue XU Rui YE ShiLi HUSSAIN Sabir JI Wei cheng Peng LI YanJun SUGAWARA Yasuhiro cheng ZhiHai CAS Center for Excellence in Nanoscience and Key Laboratory of Standardization and Measurement for Nanotechnology National Center for Nanoscience and Technology Beijing 100190 China Department of Physics Renmin University of China Beijing 100872 China The State Key Laboratory of Digital Manufacturing Equipment and Technology Department of Instrument Science and Technology School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China University of Chinese Academy of Sciences Belting 100049 China Asylum Research Santa Barbara 93117 USA Department of Applied Physics Graduate School of Engineering Osaka University Osaka 565-0871 Japan

In atomic force microscopy(AFM), high-frequency components consisted in dynamic tip-sample interaction have been recently demonstrated as a promising technique for exploring more extensive material properties. Here we present an exploratory study of high harmonic atomic force microscopy by force-spectroscopy and high harmonic imaging. Since these components are very weak compared to the fundamental response, we firstly designed a high harmonic cantilever by tuning the second order flexural resonance frequency to an integer 6 times of its fundamental mode(i.e. ω_2=6ω_1). Moreover, it is verified that high harmonic can discern extra features than topographies on different samples with amplitude/frequency modulation(AM/FM) dynamic AFM mode. In AM mode, the first resonance amplitude and 6 th harmonic amplitude were discussed. The 6 th harmonic is more sensitive than the first order response. In FM mode, it is noted that the decaying rate of the 6 th harmonic frequency is approximately 6 multiples to the slope of the fundamental frequency shift when the tip approaches to the surface of sample. This non-destructive method was also adopted to investigate the local interlayer coupling and intercalation in the two-dimensional graphene films tentatively.

关键词： high harmonic AFM high harmonic cantilever dynamic AFM

Modeling effects of temperature and precipitation on carbon characteristics and GHGs emissions in Abies fabric forest of subalpine

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Journal of Environmental Sciences 2008年第3期20卷 339-346页

作者： LU Xuyang cheng Genwei XIAO Feipeng FAN Jihui Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Abies fabric forest in the eastern slope of Gongga mountain is one type of subalpine dark coniferous forests of southwestern China. It is located on the southeastern edge of the Qinghai-Tibet plateau and is sensitive to climatic changes. A process-oriented biogeochemical model, Forest-DNDC, was applied to simulate the effects of climatic factors, temperature and precipitation changes on carbon characteristics, and greenhouse gases （GHGs） emissions in A. fabric forest. Validation indicated that the Forest-DNDC could be used to predict carbon characteristics and GHGs emissions with reasonable accuracy. The model simulated carbon fluxes, soil carbon dynamics, soil CO2, N2O, and NO emissions with the changes of temperature and precipitation conditions. The results showed that with variation in the baseline temperature from -2℃ to ＋2℃, the gross primary production （GPP） and soil organic carbon （SOC） increased, and the net primary production （NPP） and net ecosystem production （NEP） decreased because of higher respiration rate. With increasing baseline precipitation the GPP and NPP increased slightly, and the NEP and SOC showed decreasing trend. Soil CO2 emissions increased with the increase of temperature, and CO2 emissions changed little with increased baseline precipitation. With increased temperature and decreased baseline temperature, the total annual soil N2O emissions increased. With the variation of baseline temperature from -2℃ to ＋2℃, the total annual soil NO emissions increased. The total annual N2O and NO emissions showed increasing trends with the increase of precipitation. The biogeochemical simulation of the typical forest indicated that temperature changes strongly affected carbon fluxes, soil carbon dynamics, and soil GHGs emissions. The precipitation was not a principal factor affecting carbon fluxes, soil carbon dynamics, and soil CO2 emissions, but changes in precipitation could exert strong effect on soil N2O and NO emissions.

关键词： carbon characteristics greenhouse gases (GHGs) Forest-DNDC Abies fabric forest

Modeling oxidation damage of continuous fiber reinforced ceramic matrix composites

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Acta Mechanica Sinica 2011年第3期27卷 382-388页

作者： cheng-Peng Yang Gui-Qiong Jiao Bo Wang Department of Engineering Mechanics Northwestern Polytechnical University 710129 Xi'an China

For fiber reinforced ceramic matrix composites（CMCs）,oxidation of the constituents is a very important damage type for high temperature applications. During the oxidizing process,the pyrolytic carbon interphase gradually recesses from the crack site in the axial direction of the fiber into the interior of the material. Carbon fiber usually presents notch-like or local neck-shrink oxidation phenomenon,causing strength degradation. But,the reason for SiC fiber degradation is the aw growth mechanism on its surface. A micromechanical model based on the above mechanisms was established to simulate the mechanical properties of CMCs after high temperature oxidation. The statistic and shearlag theory were applied and the calculation expressions for retained tensile modulus and strength were deduced,respectively. Meanwhile,the interphase recession and fiber strength degradation were considered. And then,the model was validated by application to a C/SiC composite.

关键词： CMCs- Oxidation- Interface- Mechanical properties - Micromechanical model

Spatiotemporal characteristics of the expansion of an urban agglomeration and its effect on the eco-environment: Case study on the northern slope of the Tianshan Mountains

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Science China Earth Sciences 2019年第9期62卷 1461-1472页

作者： Chuanglin FANG Qian GAO Xiaolei ZHANG Weiguo cheng Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Resources and Environmental Science Xinjiang University Urumqi 830046 China Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China

Urban agglomerations, which are highly integrated urban groups, form during the advanced stages of industrialization and urban development. The urban agglomeration on the northern slope of the Tianshan Mountains is one of the 19 urban agglomerations promoted by China’s 13th Five-Year Plan and a key area of urbanization in Xinjiang. Based on remote sensing data, we analyzed the expansion of construction land in the urban agglomeration on the northern slope of the Tianshan Mountains and its effect on ecological value in 1980–2015. The results show that the expansion of construction land significantly affected ecological value in the study area over the past 35 years. Among land use types, grassland was the dominant contributor to changes in ecological value;its contribution rate reached 66.27% with an interannual variation of only 5%. The contribution rate of urban and rural residential land along with industrial and mining lands was very low(0.82%), while the interannual variation was large(86%). The area of construction land in the urban agglomeration expanded from 1,067 to 2,586 km^2, and the conversions of different land use types had different effects on ecological value. Among land use types, the conversions of lowcoverage grassland and dry land made the largest contributions to changes in ecological value. During the study period, a total of 1,685 km^2 of ecological land, 69.91% of which belonged to cultivated land and grassland, was converted into construction land.A total area of 1,082 km^2 of dry land and low-coverage grassland was converted into construction land, accounting for 64.21% of the total ecological land that was converted into construction land. In 2000–2015, the area of urban construction land increased significantly along with the proportion of unused land, including gobi(172 km^2), bare land(65 km^2), and salt-affected land(65 km^2), being converted into construction land. In contrast, the area of construction land that was converted into ecol

关键词： Urban agglomeration Tianshan Mountains Spatial expansion Temporal and spatial evolution Ecological environmental effect