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Incubation and development of corrosion in microstructures of low alloy steels under a thin liquid film of NaCl aqueous solution

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 748-755页

作者： wen-hua Zhang Shan-wu Yang Jia Guo Zhi-yong Liu Xin-lai He School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Electrochemical measurement, optical microscopy, and scanning electron microscopy were employed to investigate the corrosion behavior of some low alloy steels. The steels were held under a thin liquid film of 0.5wt% NaCl aqueous solution. It is found that the steels with the same chemical composition but different micmstructures exhibit obviously different corrosion behaviors. However, the corrosion behavior of the steels with different compositions but the same microstructnres may be similar in the present investigation. The corrosion rate of bainite is slower than that of ferrite and pearlite. The corrosion products of bainite are uniform and fine. The size of carbon-rich phases produces a great impact on the corrosion of the steels, whether in the initial stage or in the long tenn. It is easy to induce large pitting for carbon-rich phases with large size, which damages the compactness of the rust layer.

关键词： alloy steel microstructure atmospheric corrosion liquid films scanning electron microscope

Binding of Pyrene to Different Molecular Weight Fractions of Dissolved Organic Matter:Effects of Chemical Composition and Steric Conformation

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Chemical Research in Chinese Universities 2012年第4期28卷 624-630页

作者： wu Ji-zhou SUN Hong-wen WANG Cui-ping LI yong-hong Key Laboratory of Pollution Processes and Environmental Criteria Ministry of EducationCollege of Environmental Science and Engineering State Key Laboratory of Elemento-Organic Chemistry Research Institute of Elemento-Organic ChemistryNankai UniversityTianjin 300071P.R.China

The binding constant（KDOM） of pyrene onto different molecular weight（Mw） fractions of a dissolved organic matter（DOM） extract from an estuarine sediment was measured via a fluorescence quenching method,and the possible binding mechanisms were *** influence of water chemical parameters on pyrene binding was studied to elucidate the effects of DOM steric *** fraction with larger M w（14000） showed a greater KDOM（2.02×10 5） than that with smaller Mw did,and the KDOMs were 1.16×105 and 1.13×105 for the fractions with M w of 1000―14000 and 1000,*** K DOM s of different M w DOM fractions were correlated positively with the atomic ratio of C/H and absorbance at 280 nm;while a negative correlation existed between K DOM and（O＋C）/N（atomic ratio）,and K DOM and O-containing *** correlations indicate the positive influence of aromatic structure and the negative effect of polarity on DOM binding *** spectroscopy revealed that specific interactions existed between pyrene and the DOM fraction with larger M W besides hydrophobic partition,i.e.,NH-π interaction in DOM moiety（1000―14000） and π-π electron donor acceptor（EDA） forces in DOM moiety（14000）.KDOM varied in a complex pattern with increasing cation concentration and pH,which could be explained by the change in DOM steric *** aggregates favored the lipophilic partition of ***,the accessibility to some interior binding sites became low when the aggregate was too large,leading to a reduced KDOM.

关键词： Dissolved organic matter Conformation Water chemistry Pyrene Binding constant

Mapping winter wheat using phenological feature of peak before winter on the North China Plain based on time-series MODIS data

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Journal of Integrative Agriculture 2017年第2期16卷 348-359页

作者： TAO Jian-bin wu wen-bin ZHOU yong WANG Yu JIANG Yan Key Laboratory of Agri-informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences Key Laboratory for Geographical Process Analysis & Simulation of Hubei Province/School of Urban and Environmental Sciences Central China Normal University

By employing the unique phenological feature of winter wheat extracted from peak before winter （PBW） and the advantages of moderate resolution imaging spectroradiometer （MODIS） data with high temporal resolution and intermediate spatial resolution, a remote sensing-based model for mapping winter wheat on the North China Plain was built through integration with Landsat images and land-use data. First, a phenological window, PBW was drawn from time-series MODIS data. Next, feature extraction was performed for the PBW to reduce feature dimension and enhance its information. Finally, a regression model was built to model the relationship of the phenological feature and the sample data. The amount of information of the PBW was evaluated and compared with that of the main peak （MP）. The relative precision of the mapping reached up to 92% in comparison to the Landsat sample data, and ranged between 87 and 96% in comparison to the statistical data. These results were sufficient to satisfy the accuracy requirements for winter wheat mapping at a large scale. Moreover, the proposed method has the ability to obtain the distribution information for winter wheat in an earlier period than previous studies. This study could throw light on the monitoring of winter wheat in China by using unique phenological feature of winter wheat.

关键词： time-series MODIS data phenological feature peak before wintering winter wheat mapping

Diffuse Interstellar Bandsλ6379,λ6614,andλ6660 in the LAMOST-MRS Spectra

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Research in Astronomy and Astrophysics 2022年第8期22卷 85-102页

作者： Ke-Fei wu A-Li Luo Jian-Jun Chen wen Hou yong-Heng Zhao CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Information Management&Institute for Astronomical Science Dezhou UniversityDezhou 253023China

Diffuse interstellar bands(DIBs)have always been a mysterious existence in astronomical *** this work,we provide more DIB samples to slightly uncover this *** the LAMOST medium-resolution survey(MRS)spectra,we detected three DIBsλ6379,λ6614,andλ6660,obviously superimposed on the spectra of11,003 *** spectra cover spectral types from O to K,which can provide a large number of candidates for further research on *** sample shows a clear positive correlation between the strength of DIBs and extinction,which agrees with the result in the *** addition,there exist two peaks in each of the velocity distribution of these three DIBs,and the velocity differences between two peaks of each pair are *** reason for the two velocity components is due to the Galactic rotation.

关键词： ISM:molecules methods:data analysis (ISM:)dust extinction

EcR/USP-1-mediated ecdysteroid signaling regulates wolf spider(Pardosa pseudoannulata) development and reproduction

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Zoological Research 2023年第1期44卷 43-52页

作者： Zhi-Ming Yang Yang-Yang Yan yong wu Na Yu Ze-wen Liu Key Laboratory of Integrated Management of Crop Diseases and Pests(Ministry of Education) College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu 210095China

Lycosidae females demonstrate meticulous maternal care of offspring by carrying egg sacs and juvenile spiderlings during the reproductive stage. Nuclear receptors(NRs), especially the ecdysone receptor(EcR) and ultraspiracle(USP), have attracted considerable attention in the regulation of arthropod development and reproduction due to their pivotal roles in ecdysteroid signaling cascades. In the present study, 23 NRs, including one EcR and two USPs, were identified in the genome of the predatory wolf spider Pardosa pseudoannulata. RNA interference(RNAi) targeting EcR and USP-1inhibited spiderling development and resulted in nonviable eggs in the egg sacs. EcR and USP-1responded to changes in ecdysteroid levels, and interference in ecdysteroid biosynthesis led to similar phenotypes as ds EcR and ds USP-1 *** findings suggest that EcR/USP-1-mediated ecdysteroid signaling regulates P. pseudoannulata development and reproduction. The *** females with suppressed ecdysteroid signaling proactively consumed their non-viable egg sacs, resulting in a 7.19 d shorter first reproductive cycle than the controls. Termination of the failed reproductive cycle enabled the spiders to produce a new egg sac more rapidly. This reproductive strategy may partially rescue the reduction in population growth due to non-viable eggs and compensate for the physiological expenditure of wasted maternal care, which would be beneficial for the conservation of *** populations and their natural control of insect pests.

关键词： Pardosa pseudoannulata Ecdysone receptor Ultraspiracle Development Reproduction

2004-2008年株洲地区围产儿出生缺陷监测结果与对策探讨

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实用预防医学 2009年第2期16卷 480-482页

作者：宋兵文陈勇兰吴玲陈科黄爱媛湖南省株洲市妇幼保健院湖南株洲412008

目的了解株洲地区围产儿出生缺陷现状,探讨出生缺陷发生的可能影响因素及降低出生缺陷发生的对策。方法对株洲地区2004-2008年28家医疗保健机构的围产儿出生缺陷监测资料进行分析。结果株洲地区2004-2008年围产儿出生缺陷发生率为145.78... 详细信息

目的了解株洲地区围产儿出生缺陷现状,探讨出生缺陷发生的可能影响因素及降低出生缺陷发生的对策。方法对株洲地区2004-2008年28家医疗保健机构的围产儿出生缺陷监测资料进行分析。结果株洲地区2004-2008年围产儿出生缺陷发生率为145.78/万,5年间出生缺陷发生率呈上升趋势。前5位出生缺陷类型依次为先心病、唇腭裂、指(趾)畸形、先天性脑积水、外耳畸形。孕母年龄小于20岁、大于35岁,出生缺陷发生率明显增高;男婴出生缺陷发生率明显高于女婴;产前B超监测对及早发现胎儿畸型,降低病残儿死亡率和围产儿死亡率有着重要的作用;出生缺陷发生与孕早期异常情况、遗传有一定的相关性。结论做好出生缺陷监测,加强出生缺陷的综合预防工作,有利于减少出生缺陷的发生。

关键词：出生缺陷监测对策

Numerical study on wave loads and motions of two ships advancing in waves by using three-dimensional translating-pulsating source

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Acta Mechanica Sinica 2013年第4期29卷 494-502页

作者： yong Xu wen-Cai Dong Department of Naval Architecture Naval University of Engineering

A frequency domain analysis method based on the three-dimensional translating-pulsating （3DTP） source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course in waves. Two experiments are carried out respectively to mea- sure the wave loads and the free motions for a pair of side-by- side arranged ship models advancing with an identical speed in head regular waves. For comparison, each model is also tested alone. Predictions obtained by the present solution are found in favorable agreement with the model tests and are more accurate than the traditional method based on the three dimensional pulsating （3DP） source Green function. Numer- ical resonances and peak shift can be found in the 3DP pre- dictions, which result from the wave energy trapped in the gap between two ships and the extremely inhomogeneous wave load distribution on each hull. However, they can be eliminated by 3DTP, in which the speed affects the free sur- face and most of the wave energy can be escaped from the gap. Both the experiment and the present prediction show that hydrodynamic interaction effects on wave loads and free motions are significant. The present solver may serve as a validated tool to predict wave loads and motions of two ves- sels under replenishment at sea, and may help to evaluate the hydrodynamic interaction effects on the ships safety in replenishment operation.

关键词： Hydrodynamic interaction - Wave loads ~Ship motions ~ Model test ~ Three-dimensional translating-pulsating source ~ Underway replenishment

Photodimerization-induced transition of helixes to vesicles based on coumarin-12-crown-4

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Chinese Chemical Letters 2022年第8期33卷 4033-4036页

作者： Hui-Juan Wang Heng-Yi Zhang wen-wen Xing Huang wu yong-Liang Cui Yu Liu Department of Chemistry State Key Laboratory of Elemento-Organic ChemistryNankai UniversityTianjin 300071China Department of Chemistry Northwestern UniversityEvanstonIL 60208United States

Rational construction of fine-tuning and precisely controllable topological nanostructures based on supramolecular self-assembly system remains a ***,coumarin-12-crown-4(1)as a building block was synthesized by one-pot method and showed reversible high stereo-selective photodimerization(anti-head-to-head dimer(anti-HH-1):syn-head-to-head dimer(syn-HH-1)=10.8:1)and *** nanobelts were formed by the self-assembly of 1 through asymmetrical H-bonds,which were in concordance with the crystal state *** irradiation with 365 nm light,these nanobelts transformed into nanoballs which were constructed by three building ***,we investigated the photoreaction of 1 and got two pure covalent dimers(anti-HH-1 and syn-HH-1).The anti-HH-1 selfassembled into hollow *** transformation of superstructures based on photo-controlled multiple blocks shines a light to the research on the relationship between molecules and superstructures.

关键词： Reversible photodimerization Superstructures Coumarin Supramolecular self-assembly Molecular stacking

New Families of Rational Form Variable Separation Solutions to(2+1)-Dimensional Dispersive Long Wave Equations

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Communications in Theoretical Physics 2009年第5期51卷 789-793页

作者： wen Xiao-yong Department of Mathematics College of Sciences Beijing Information Science and Technology University Beijing 100192China

With the aid of symbolic computation system Maple, some families of new rational variable separation solutions of the （2＋1）-dimensional dispersive long wave equations are constructed by means of a function transformation, improved mapping approach, and variable separation approach, among which there are rational solitary wave solutions, periodic wave solutions and rational wave solutions.

关键词： improved mapping approach variable separation method (2+1)-dimensional dispersive long wave equations symbolic computation