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Ant colonization increased total mercury but reduced methylmercury contents in boreal mires, Northeast China

Journal of Environmental Sciences 2022年第9期34卷 50-58页

作者： Zhongsheng Zhang Xuehui Zhang Yuan Xin haitao wu Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130012China University of Chinese Academy of Sciences Beijing 100049China Shengyang University Shenyang 110044China

Soil macroinvertebrates as ecosystem engineers play significant, but largely ignored, roles in affecting mercury(Hg) cycle by altering soil physical-chemical properties. Ant is likely expanded into boreal mires with climate warming, however, its impacts on Hg cycle remained poorly understood. We compared total Hg(THg) and methylmercury(Me Hg) contents in soils from antmounds( Lasius flavus) and the nearby ambient in a boreal mire in Northeast China. The present work seeks to unravel factors that controlling Me Hg levels in case of ant appearance or absence. The average THg was 179 μg/kg in the ant mound and was 106.1 μg/kg in nearby soils, respectively. The average Me Hg was 10.9 μg/kg in the ant mound and was 12.9 μg/kg in nearby soils, respectively. The ratios of Me Hg to THg(%Me Hg) were 7.61% in ant mounds and 16.75% in nearby soils, respectively. Ant colonization caused THg enrichment and Me Hg depletion, and this change was obvious in the 10-20 cm depth soil layer where ants mainly inhabited. Spectrometry characteristics of soil dissolved organic matter(DOM) exert a stronger control than microorganisms on Me Hg variation in soils. A structural equation model revealed that the molecular weight of DOM inhibited Me Hg irrespective of ant presence or absence, while humification conducive to Me Hg significantly in ant mound soils. Microorganisms mainly affected Hg methylation by altering the molecular weight and humification of DOM. We propose that the effects of ant colonization on Me Hg rested on DOM feature variations caused by microorganisms in boreal mires.

关键词： Ant colonization Mercury Methylmercury Boreal mire DOM spectrometry

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A Lightweight ABE Security Protection Scheme in Cloud Environment Based on Attribute Weight

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Computers, Materials & Continua 2023年第8期76卷 1929-1946页

作者： Lihong Guo Jie Yang haitao wu Department of Information and Communications Engineering Nanjing Institute of TechnologyNanjing211167China

Attribute-based encryption(ABE)is a technique used to encrypt data,it has the flexibility of access control,high security,and resistance to collusion attacks,and especially it is used in cloud security ***,a large number of bilinear mappings are used in ABE,and the calculation of bilinear pairing is *** there is the problem of low *** the other hand,the decryption key is not uniquely associated with personal identification information,if the decryption key is maliciously sold,ABE is unable to achieve accountability for the *** practical applications,shared message requires hierarchical sharing in most cases,in this paper,we present a message security hierarchy ABE scheme for this ***,attributes were grouped and weighted according to the importance of attributes,and then an access structure based on a threshold tree was constructed according to attribute *** method saved the computing time for decryption while ensuring security and on-demand access to information for *** addition,with the help of computing power in the cloud,two-step decryption was used to complete the access,which relieved the computing and storage burden on the client ***,we simulated and tested the scheme based on CP-ABE,and selected different security levels to test its *** security proof and the experimental simulation result showthat the proposed scheme has high efficiency and good performance,and the solution implements hierarchical access to the shared message.

关键词： Attribute-based encryption cloud security message hierarchy attribute weight access control

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Influence of isothermal bainitic processing on the mechanical properties and microstructure characterization of TRIP steel

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Journal of University of Science and Technology Beijing 2008年第5期15卷 574-579页

作者： haitao Jiang Hubin wu Di Tang Qiang Liu National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing Beijing 100083 China

The mechanical properties of transformation induced plasticity （TRIP） steel are strongly affected by the conditions of iso-thermal bainitic processing. The multiphase microstructure of TRIP steel under different conditions of isothermal bainitic processing was investigated using OM,SEM,XRD and TEM. The volume fraction of retained austenite and the carbon content in austenite were determined quantitatively using X-ray diffraction patterns. The relationship between mechanical properties and isothermal bainitic processing parameters was investigated. The stability of retained austenite was analyzed by the volume fraction of retained austenite and the carbon content in retained austenite. The experimental results show that the multiphase microstructure consists of ferrite,bainite and metastable retained *** obtain good mechanical properties,the optimal conditions of isothermal bainitic temperature and holding time are 410-430°C and 180-240 s,respectively. After isothermal bainitic processing under the optimal conditions,the corresponding volume fraction of retained austenite is 5vol%-15vol%,which can provide enough retained austenite and plastic stability for austenite with high carbon content.

关键词： transformation induced plasticity steel isothermal bainitic processing mechanical properties microstructure

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The Cerebellum Modulates Mood with Movement

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Neuroscience Bulletin 2024年第9期40卷 1396-1398页

作者： Shaofei Jiang haitao wu Department of Neurobiology Beijing Institute of Basic Medical SciencesBeijing100850China

Anxiety disorder stands as the most prevalent emotional disorder on a global scale[1].Traditional pharmacological interventions for anxiety disorder frequently encounter obstacles such as drug resistance and adverse reactions,presenting significant hurdles in clinical *** the well-established understanding that exercise can alleviate anxiety,the precise neural mechanisms underpinning this effect remain ***,there remains an unresolved clinical imperative to determine the optimal exercise regimen to augment its therapeutic efficacy in anxiety *** conventionally regarded as primarily involved in fine-tuning motor functions,recent research has shed light on the cerebellum's role in emotion and cognition regulation[2-4].Additionally,the amygdala is recognized for its pivotal role in bidirectional anxiety modulation[5].

关键词： clinical precise spite

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Influence of CaF_2 on the structure and dielectric properties of Ag(Nb_(0.8)Ta_(0.2))O_3 ceramics

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Rare Metals 2010年第1期29卷 50-54页

作者： CAO Lifeng LI Lingxia ZHANG Ping wu haitao School of Electronic and Information Engineering Tianjin University Tianjin 300072 China School of Materials Science and Engineering University ofJinan Jinan 250022 China

Ag（Nb0.8Ta0.2）O3 ceramics were prepared by the traditional solid-state reaction method. The effect of CaF2 addition on the structure and dielectric properties of Ag（Nb0.8Ta0.2）O3 ceramics was investigated. The addition of CaF2 led the ceramics to a larger grain size and distortion of lattice. With the addition of 4.5 wt.% CaF2, the permittivity of the ceramics increased from 442 to 1028, the dielectric loss decreased sharply from 6.12 × 10^-3 to 8.6 × 10^-4, and the temperature coefficient of capacitance decreased from 1834 ppm/℃ to -50 ppm/℃ （at 1 MHz）. These results indicated that the high permittivity was related with a large grain size, a low grain boundary density, and the weak Ta-O or Nb-O bond strength caused by the addition of CaF2.

关键词： microwave materials Ag(Nb,Ta)O3 solid-state reaction method dielectric properties

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Ecology of testate amoebae and their potential use as palaeohydrologic indicators from peatland in Sanjiang Plain, Northeast China

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Frontiers of Earth Science 2014年第4期8卷 564-572页

作者： Lihong SONG Hongkai LI Kehong WANG Donghui wu haitao wu Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130102 China University of Chinese Academy of Sciences Beijing 100049 China Institute for Peat and Mire Research Northeast Normal University Changchun 130024 China

Testate amoebae are sensitive indicators of substrate moisture in peaflands. Over the last decades, they have been studied to reconstruct hydrological changes since the Holocene. However, these studies have been geographically restricted to North America and Europe. We conducted the first investigation of testate amoebae on the largest continental fresh water wetland in the Sanjiang Plain, China. The objectives of this study were to provide baseline data on the ecology of testate amoebae in the peatlands of Northeast China and to assess the potential of using them as environmental indicators in this ecosystem. We examined modem testate amoeba assemblages and species-environmental relationships at 46 microsites within 5 waterlogged depressions. The environmental parameters measured included： depth to water table, pH, and loss on ignition. The results showed that the dominant species were Trinema complanatum type, Euglypha rotunda type, Euglypha strigosa type, and Centropyxis cassis type. Redundancy analysis demonstrates that water table depth has the most important effect on testate amoeba assemblages, explaining 16.7% （p=0.002） of the total variance, pH was not a statistically significant factor for testate amoeba assemblages. Weighted averaging and weighted averaging partial least squares models were used to build transfer functions for depth to water table. The best performing transfer function was generated by the weighted averaging partial least squares model with an r^2LOSO of 0.62 and RMSEPLoso of 6.96 era. Results indicate that testate amoebae in waterlogged depression peatland have the potential to be used as indicators for hydrological changes and for palaeohydrologic reconstructions in the Sanjiang Plain.

关键词： palaeoecology peatland testate amoebae,transfer function Sanjiang Wetland Northeast China

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Crystal structure and enhanced microwave dielectric properties of the Ce_(2)[Zr_(1−x)(Al_(1/2)Ta_(1/2))_(x)]_(3)(MoO_(4))_(9) ceramics at microwave frequency

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Journal of Advanced Ceramics 2022年第3期11卷 392-402页

作者： Chao FENG Xu ZHOU Bingjing TAO haitao wu Shifeng HUANG Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials University of JinanJinan250022China School of Environmental and Material Engineering Yantai UniversityYantai264005China

Dense microwave dielectric ceramics of Ce_(2)[Zr_(1−x)(Al_(1/2)Ta_(1/2))_(x)]_(3)(MoO_(4))_(9)(CZMAT) (x = 0.02–0.10) were prepared by the conventional solid-state route. The effects of (Al1/2Ta1/2)^(4+) on their microstructures, sintering behaviors, and microwave dielectric properties were systematically investigated. On the basis of the X-ray diffraction (XRD) results, all the samples were matched well with Pr_(2)Zr_(3)(MoO_(4))_(9) structures, which belonged to the space group R3¯c. The lattice parameters were obtained using the Rietveld refinement method. The correlations between the chemical bond parameters and microwave dielectric properties were calculated and analyzed by using the Phillips—Van Vechten—Levine (P—V—L) theory. Excellent dielectric properties of Ce_(2)[Zr_(0.94)(Al_(1/2)Ta_(1/2))_(0.06)]_(3)(MoO_(4))_(9) with a relative permittivity (ε_(r)) of 10.46, quality factor (Q × f) of 83,796 GHz, and temperature coefficient of resonant frequency (τ_(f)) of −11.50 ppm/℃ were achieved at 850 ℃.

关键词： microwave dielectric ceramics Ce_(2)[Zr_(1−x)(Al_(1/2)Ta_(1/2))_(x)]_(3)(MoO_(4))_(9)(CZMAT) Phillips-Van Vechten-Levine(P-V-L)theory low sintering temperature

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Impacts of Soil Fauna on Litter Decomposition at Different Succession Stages of Wetland in Sanjiang Plain,China

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Chinese Geographical Science 2009年第3期19卷 258-264页

作者： wu haitao LU Xianguo JIANG Ming BAO Xiao Key Laboratory of Wetland Ecology and Environment Institute of Northeast Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Litter decomposition is the key process in nutrient recycling and energy flow. The present study examined the impacts of soil fauna on decomposition rates and nutrient fluxes at three succession stages of wetland in the Sanjiang Plain, China using different mesh litterbags. The results show that in each succession stage of wetland, soil fauna can obviously increase litter decomposition rates. The average contribution of whole soil fauna to litter mass loss was 35.35%. The more complex the soil fauna group, the more significant the role of soil fauna. The average loss of three types of litter in the 4mm mesh litterbags was 0.3-4. l times that in 0.058ram ones. The decomposition function of soil fauna to litter mass changed with the wetland succession. The average contribution of soil fauna to litter loss firstly decreased from 34.96% （Carex lasiocapa） to 32.94% （Carex rneyeriana）, then increased to 38.16% （Calamagrostics angustifolia）. The contributions of soil fauna to litter decomposition rates vary according to the litter substrata, soil fauna communities and seasons. Significant effects were respectively found in August and July on C. angustifolia and C. lasiocapa, while in June and August on C. meyeriana. Total carbon （TC）, total nitrogen （TN） and total phosphorus （TP） contents and the C/N and C/P ratios of decaying litter can be influenced by soil fauna. At different wetland succession stages, the effects of soil fauna on nutrient elements also differ greatly, which shows the significant difference of in- fluencing element types and degrees. Soil fauna communities strongly influenced the TC and TP concentrations of C. meyeriana litter, and TP content of C. lasiocapa. Our results indicate that soil fauna have important effects on litter decomposition and this influence will vary with the wetland succession and seasonal variation.

关键词： wetland invertebrate soil fauna litter decomposition nutrient dynamics

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Signal structure of the Chinese Area Positioning System

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Science China(Physics,Mechanics & Astronomy) 2009年第3期52卷 412-422页

作者： LU XiaoChun wu haitao BIAN YuJing HUA Yu National Time Service Center Chinese Academy of SciencesXi’an 710600China

Proper signal structure is very important in the navigation, positioning, and time services of a satellite navigation system. In this paper, the carrier wave characteristics, ranging code functions, BOC modulation, navigation data rate, the error-correcting methods, and signal channel resource allocation are discussed in terms of the technical characteristics of the transforming satellite navigation system and the resources of communication satellites. The results show that dual-frequency of C band in the Chinese Area Positioning System (CAPS), compound ranging code, a combination of the coarse code and precise code, BOC modulation, separate-channel transmission of different users are compatible with the satellite navigation system at present. The experiments show that the current signal structure can meet the demand of CAPS.

关键词： signal structure ranging code BOC modulation navigation

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A Macroinvertebrate Multimetric Index for the Bioassessment of Wetlands Adjacent to Agriculture Fields in the Sanjiang Plain, China

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Chinese Geographical Science 2019年第6期29卷 974-984页

作者： wu haitao LU Kangle LYU Xianguo XUE Zhenshan Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China

Adjacent intensive agriculture disturbs the natural condition of ***, to assess the effect of this agriculture on wetlands, few studies have used indices based on aquatic ***-metric indices(MMIs) have been successfully used to assess freshwater ecosystems worldwide and are an important management tool, but little is known about their applicability in the Sanjiang Plain, Northeast *** this study, we developed a MMIs for aquatic invertebrates to assess freshwater wetlands in this *** aquatic invertebrate assemblages were sampled in 27 wetlands in the Sanjiang Plain that included those in natural reserves and those affected by adjacent, intensive ***-four candidate metrics were initially reviewed and screened before four core metrics were selected: total number of taxa, number of Hemiptera taxa, proportion of Gastropoda, and proportion of ***-Whitney U tests, Box and Whisker plots, correlation analyses, and redundant metric tests were used to assess the ability of metrics to distinguish among reference and impaired *** ordinal rating categories for wetland were defined: poor, fair, good, and *** the impaired freshwater wetlands, 76.2% were in poor or fair *** MMIs was robust in discriminating reference wetlands from impaired wetlands and therefore have potential as a biomonitoring tool to assess the condition and to guide the restoration efforts of freshwater wetlands in Northeast China.

关键词： bio-assessment Hemiptera Mollusca multi-metric indices(MIS) bioassessment of wetland the Sanjiang Plain

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