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Surface Reaction of TiAl with Water Vapor and Oxygen

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Journal of Materials science & Technology 2003年第4期19卷 334-336页

作者： YexinCHEN XiaojingWAN WeixinXU InstituteofMaterials ShanghaiUniversityShanghai200072China ShanghaiIronandSteelResearchInstitute Shanghai200940China

The interaction of water vapor and oxygen with TiAI-based alloy has been studied with Auger electron spectroscopy and X-ray photoelectron spectroscopy. The results indicate that both surface reactions initiate at a very short exposure (about 6×10-7 Pa·s) and the oxides Al2O3 and TiO2 form in the surface reactions. In the oxidizing reaction, the water vapor reacts firstly with Al, and then reacts with Ti after certain exposure. The surface reaction of Al with water vapor may be responsible for the environmental embrittlement at room temperature in TiAI-based alloy.

关键词： Surface reaction XPS TiAl alloy

Close-in weapon system planning based on multi-living agent theory

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Defence Technology（防务技术） 2022年第7期18卷 1219-1231页

作者： Tang Tang Yue Wang Li-juan Jia Jin Hu Cheng Ma School of Information and Electronic Beijing Institute of TechnologyBeijing100081China

The close-in weapon system(CIWS)is a combat system that faces a complex environment full of dynamic and unknown challenges,whose construction and planning require a systematic design *** agent(MLA)theory is a methodology for the combat system design,which uses the livelihood degree to evaluate the multi-dimensional long-term operational effectiveness of the system;whereas,there is still no uniform quantization framework for the livelihood degree,and the adjustment methods of livelihood degree need to be further *** this paper,we propose the uniform quantization framework for the livelihood degree and detailed discuss the methods of livelihood *** on the MLA theory,the multi-dimensional operational effectiveness of the missile-gun integrated weapon system(MGIWS)is analyzed,and the long-term combat effectiveness against the saturation attack is ***,the planning problem of the equipment deployment and configuration is *** objectives,including the overall livelihood degree and cost-effectiveness(CE),are proposed,and the optimization method based on genetic algorithm(GA)is studied for the planning problem.

关键词： Multi-living agent theory Close-in weapon system Effectiveness evaluation Livelihood degree Queueing system Missile-gun integrated weapon system

Experimental Study of Flow Patterns and Improved Configurations for Pulsating Heat Pipes

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Journal of Thermal science 2007年第1期16卷 56-62页

作者： Shi LIU Jingtao LI Xiangyuan DONG Huanzhuo CHEN Institute of Engineering Thermophysics Chinese Academy of Sciences EO. Box 2706 Beijing 100080 China

A series of experiments were performed on three types of closed loop pulsating heat pipes （PHPs）, intending to investigate various kinds of flow patterns, and to develop some improved configurations for the PHPs. Optical visualization results indicated that there might exist three flow patterns, i.e. bubble-liquid slug flow, semi-annular flow and annular flow, corresponding to different working conditions. For a given geometry and an adequate fill ratio, the PHPs had the self-adjusting characteristic for the flow patterns （from slug flow to semi-annular and then to annular flow） to meet the demands of the increasing heat input. Two special configurations, one with alternately varying channel diameter, the other equipped with one section of thicker tube, were found to be advantageous in establishing and maintaining reliable circulation of the working fluid. The thermal performance of the PHPs was examined over a range of working conditions. Comparing with the normal PHP with uniform diameter, either of the improved PHPs exhibited higher thermal performance.

关键词： pulsating heat pipe flow patterns improved configurations.

Optical flow-based method to estimate internal wave parameters from X-band marine radar images

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Acta Oceanologica Sinica 2022年第9期41卷 149-157页

作者： Jinghan Wen Zhongbiao Chen Yijun He School of Marine sciences Nanjing University of Information Science&TechnologyNanjing210044China Key Laboratory of Space Ocean Remote Sensing and Applications National Satellite Ocean Application ServiceBeijing100081China

The velocity and direction of internal waves(IWs) are important parameters of the ocean,however,traditional observation methods can only obtain the average parameters of IWs for a single location or large ***,a new method based on optical flow is proposed to derive the phase velocity vectors of IWs from X-band marine radar ***,the X-band marine radar image sequence is averaged,and ramp correction is used to reduce the attenuation of gray values with increasing radial ***,the average propagation direction of the IWs is determined using the two-dimensional Fourier transform of the radar images;two radial profiles along this direction are selected from two adjacent radar images;and then,the average phase velocity of the IWs is estimated from these radial ***,the averaged radar images are processed via histogram equalization and binarization to reduce the influence of noise on the radar ***,a weighting factor is determined using the average phase velocity of a reference point;the phase velocities on the wave crest of the IWs are subsequently estimated via the optical flow ***,the proposed method is validated using X-band marine radar image sequences observed on an oil platform in the South china Sea,and the error of the phase velocity is calculated to be 0.000 3–0.073 8 m/*** application conditions of the proposed method are also discussed using two different types of IW packets.

关键词： internal wave X-band marine radar optical flow phase velocity

A parameterization scheme of vertical mixing due to inertial internal wave breaking in the ocean general circulation model

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Acta Oceanologica Sinica 2015年第1期34卷 11-22页

作者： FAN Zhisong SHANG Zhenqi ZHANG Shanwu HU Ruijin LIU Hailong College of Physical and Environmental Oceanography Ocean University of China The Third Institute of Oceanography State Oceanic Administration State Key Laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

Based on the theoretical spectral model of inertial internal wave breaking （fine structure） proposed previ- ously, in which the effects of the horizontal Coriolis frequency component f-tilde on a potential isopycnal are taken into account, a parameterization scheme of vertical mixing in the stably stratified interior be- low the surface mixed layer in the ocean general circulation model （OGCM） is put forward preliminarily in this paper. Besides turbulence, the impact of sub-mesoscale oceanic processes （including inertial internal wave breaking product） on oceanic interior mixing is emphasized. We suggest that adding the inertial inter- hal wave breaking mixing scheme （F-scheme for short） put forward in this paper to the turbulence mixing scheme of Canuto et al. （T-scheme for short） in the OGCM, except the region from 15°S to 15°N. The numeri- cal results ofF-scheme by usingWOA09 data and an OGCM （LICOM, LASG/IAP climate system ocean model） over the global ocean are given. A notable improvement in the simulation of salinity and temperature over the global ocean is attained by using T-scheme adding F-scheme, especially in the mid- and high-latitude regions in the simulation of the intermediate water and deep water. We conjecture that the inertial internal wave breaking mixing and inertial forcing of wind might be one of important mechanisms maintaining the ventilation process. The modeling strength of the Atlantic meridional overturning circulation （AMOC） by using T-scheme adding F-scheme may be more reasonable than that by using T-scheme alone, though the physical processes need to be further studied, and the overflow parameterization needs to be incorporated. A shortcoming in F-scheme is that in this paper the error of simulated salinity and temperature by using T-scheme adding F-scheme is larger than that by using T-scheme alone in the subsurface layer.

关键词： vertical mixing inertial internal wave fine structure horizontal Coriolis frequency component,ocean general circulation model

The effects of DDT on the feeding, respiration, survival, and reproduction of Sinocalanus tenellus(Copepoda:Calanoida)

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Acta Oceanologica Sinica 2014年第9期33卷 133-138页

作者： XU Donghui LIU Guangxing College of Physical and Environmental Oceanography Ocean University of China College of Environmental science and Engineering Ocean University of China Key Laboratory of Marine Environment & Ecology Ministry of Education Ocean University of China

DDT （dichloro-diphenyl-trichloroethane） as a type of organochlorine pesticides, is an important compo nent of pesticides pollution whose impact on the marine ecosystem is urgently to be evaluated. To investi gate the biological effects of DDT on the marine ecosystem, copepods being the main contributor of sec ondary productivity in the marine ecosystem, were selected as target animals. The influence of DDT on the feeding, respiration, survival, and reproduction of Sinocalanus tenellus （S. tenellus） was analyzed and the antioxidant enzymes activities in the individuals were measured under different exposure concentrations of DDT. The 48 h median lethal concentration （LC50） and 96 h LC50 of DDT to S. tenellus were 5.44 and 2.50 pg/dma, respectively. The filtration rates, grazing rates, and respiration of S. tenellus decreased apparently with increased DDT concentrations. under lower concentration （〈625 ng/dm3） of DDT, the activities of the antioxidant enzymes, including superoxide dismutase and catalase in the animals increased significantly compared with those in the animals without any exposure to DDT, which suggested that the antioxidant enzymes can protect the animals from oxidative damage. However, the activity of the antioxidant enzyme decreased when the animals were exposed to higher concentration （1250-2 500 ng/dma） of DDT. The sur-vival rate of both females and males was reduced when they were exposed to DDT less than 250 ng/dm3, but females showed higher survival rate than males when they are under the same concentration. The hatching ratio and the egg diameters of S. tenellus decreased significantly when they were exposed to DDT with a concentration of 25 and 250 ng/dm3, however, the cumulative egg production did not show any significant variation when the animals were exposed to the above DDT concentration. These data in the preset study suggested that exposure to DDT can cause the variation of the species composition of copepods, and further affect the ma

关键词： DDT Sinocalanus tenellus survival reproduction feeding respiration antioxidant enzyme

Microstructure and Eutectic Carbide Morphology of the High Speed Steel Strips Produced by Twin Roll Strip Casting Process

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Journal of Materials science & Technology 2003年第5期19卷 472-474页

作者： Hongshuang DI, Xiaoming ZHANG, Guodong WANG and Xianghua LIUState Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, china State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China

The M2 high-speed steel strip was produced by using the laboratory scale twin roll strip caster. The microstructure and eutectic carbide morphology of thus produced products were observed and analyzed, and the comparison of those with conventional products was carried out. The effects of the processing parameters such as the melting temperature, the pouring temperature, rolling speed and separating force on the microstructure and eutectic carbide morphology and their distribution were analyzed. The spheroidizing process of the strips in the annealing process was investigated. The relations between the growth and spheroidizing of the eutectic carbide and the annealing technology were obtained, and the mechanism of the twin roll strip casting process improving the eutectic carbide spheroidizing was discussed. The theoretical instruction for determining the subsequent treatment process was provided.

关键词： Twin roll strip casting High speed steel Eutectic carbide Microstructure

Detection of oil spill based on CBF-CNN using HY-1C CZI multispectral images

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Acta Oceanologica Sinica 2022年第7期41卷 166-179页

作者： Kai Du Yi Ma Zongchen Jiang Xiaoqing Lu Junfang Yang College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao266590China First Institute of Oceanology Ministry of Natural ResourcesQingdao266061China School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin150001China national Satellite Ocean Application Service Beijing100081China College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao266580China Technology Innovation Center for Ocean Telemetry Ministry of Natural ResourcesQingdao266061China national Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an710072China

Accurate detection of an oil spill is of great significance for rapid response to oil spill *** images have the advantages of high spatial resolution,short revisit period,and wide imaging width,which is suitable for large-scale oil spill ***,in wide remote sensing images,the number of oil spill samples is generally far less than that of seawater ***,the sea surface state tends to be heterogeneous over a large area,which makes the identification of oil spills more difficult because of various sea conditions and *** address this problem,we used the F-Score as a measure of the distance between forecast value and true value,proposed the Class-Balanced F loss function(CBF loss function)that comprehensively considers the precision and recall,and rebalances the loss according to the actual sample numbers of various *** the CBF loss function,we constructed convolution neural networks(CBF-CNN)for oil spill *** on the image acquired by the Coastal Zone Imager(CZI)of the Haiyang-1C(HY-1C)satellite in the Andaman Sea(study area 1),we carried out parameter adjustment *** contrast to experiments of different loss functions,the F1-Score of the detection result of oil emulsions is 0.87,which is 0.03–0.07 higher than cross-entropy,hinge,and focal loss functions,and the F1-Score of the detection result of oil slicks is 0.94,which is 0.01–0.09 higher than those three loss *** comparison with the experiment of different methods,the F1-Score of CBF-CNN for the detection result of oil emulsions is 0.05–0.12 higher than that of the deep neural networks,supports vector machine and random forests models,and the F1-Score of the detection result of oil slicks is 0.15–0.22 higher than that of the three *** verify the applicability of the CBF-CNN model in different observation scenes,we used the image obtained by HY-1C CZI in the Karimata Strait to carry out experiments,which include two stu

关键词： oil spills CNN classification loss function sunglint detection

The variability of surface radiation fluxes over landfast sea ice near Zhongshan station,east Antarctica during austral spring

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International Journal of Digital Earth 2019年第8期12卷 860-877页

作者： Lejiang Yu Qinghua Yang Mingyu Zhou Donald H.Lenschow Xianqiao Wang Jiechen Zhao Qizhen Sun Zhongxiang Tian Hui Shen Lin Zhang State Oceanic Administration Key Laboratory for Polar science Polar Research Institute of ChinaShanghaiPeople’s Republic of China Key Laboratory of Research on Marine Hazards Forecasting National Marine Environment Forecasting CenterBeijingPeople’s Republic of China national Center for Atmospheric Research BoulderCOUSA

Surface radiative fluxes over landfast sea ice off Zhongshan station have been measured in austral spring for five springs between 2010 and *** and upward solar radiation vary diurnally with maximum amplitudes of 473 and 290 W m^(−2),*** maximum and minimum long-wave radiation values of the mean diurnal cycle are 218 and 210 W m^(−2)for downward radiation,277 and 259 W m^(−2)for upward radiation and 125 and−52 W m^(−2)for net *** albedo has a U-shaped mean diurnal cycle with a minimum of 0.64 at *** ice thickness is in the growth phase for most spring days,but can be disturbed by synoptic *** surface temperature largely determines the occurrence of ice *** downward and upward long-wave radiation show synoptic oscillations with a 5–8 day period and intraseasonal variability with a 12–45 day *** amplitudes of the diurnal,synoptic and intraseasonal variability show some differences during the five austral springs considered *** intraseasonal and synoptic variability of downward and upward long-wave radiation are associated with the variability of cloud cover and surface temperature induced by the atmospheric circulation.

关键词： Surface radiation flux Antarctic sea ice diurnal cycle synoptic and intraseasonal variability el niño southern oscillation(ENSO)