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基于综合平差的弧形闸门几何公差分析模型

水电能源科学 2024年第9期42卷 148-151页

作者：毋新房李东明王志颖涂从刚水利部水工金属结构质量检验测试中心河南郑州450000 中国地质大学(北京)土地科学技术学院北京100083

孔口中心线是弧形闸门安装、故障诊断的几何基础,但在工程上常面临不易保存、难以复现的难题。对此,综合各埋件与孔口中心线的几何关系,基于附有参数的条件平差理论,实现了孔口中心线的准确求解;并根据弧形闸门的空间结构,建立了坐标维... 详细信息

孔口中心线是弧形闸门安装、故障诊断的几何基础,但在工程上常面临不易保存、难以复现的难题。对此,综合各埋件与孔口中心线的几何关系,基于附有参数的条件平差理论,实现了孔口中心线的准确求解;并根据弧形闸门的空间结构,建立了坐标维度具备工程含义的几何公差分析坐标系,由此提出了一种基于综合平差的弧形闸门几何公差分析模型。理论和工程实践表明,该模型可准确复现孔口中心线,并直观、高效地分析各埋件的几何公差,具有极强的工程价值和研究意义。

关键词：弧形闸门孔口中心线条件平差几何公差

Distribution　and　Transformation　of　Native　and　Added　Ni　Fractions　in　Purple　Soils　from　Sichuan　Province

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Pedosphere 1996年第2期6卷 183-192页

作者： tu cong(College of Resources and Environment,Southwest Agricultural University,Chonyqiny 630716 China) College of Resources and Environment Southwest Agricultural University Chongqing 630716 China

The distribution and transformation of added and native Ni in purple soils were investigated with both sequential extraction procedure and isotopic tracer *** distribution of added and native Ni was greatly dependent on soil *** soil PH was favorable for soluble plus exchangeable (EX) Fraction,while Fe/Mn oxides and clay for Fe/Mn oxide bound (OX) and residual (RES) fractions. The added Ni,however,has not yet reached the distribution equilibrium up to the 150th day after *** was reflected in the fact that the proportion of EX fraction from added Ni was 150%-600% as much as that of native Ni, while that of RES fraction was only about 80%.Once entering soil, the applied soluble Ni was rapidly transformed into Other fractions, but the organic complexed (OM) fraction of added Ni was relatively stable during *** carbonate bound(CAB) fraction showed a progressive increase and attained a peak value after 0-14 d of incubation and thereafter decreased gradually. The occurrence time of this peak advanced as initial soil PH increased, but the peak would disappear when initial soil pH was higher than 7.5(or containing free CaCO3). The transformation processes of the EX,OX and RES fractions could be described by Elovich and two-constant rate equstions,and the rates were positively correlated with soil pH,CEC and *** findings could explain why there are differences in ecological and environmental effects of Ni in different soils and at various intervals.

关键词： distribution Ni fraction purple soil tracer technique transformation

Insulation Design Rule for a Spacer in SF_(6)/N_(2)-filled DC Gas Insulated Apparatus

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 727-735页

作者： Hongyang Zhou Guoming Ma Meng Zhang cong Wang Youping tu Chengrong Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

A recurring challenge of a DC SF_(6)/N_(2)-filled GIS/GIL apparatus is the charge accumulation at DC *** conventional design rules and knowledge of AC spacers may not be applicable for this new type of apparatus.A novel design rule is proposed considering the effect of accumulated charge on the threshold of electric field strength being resistant to the superposed voltage.A surface charge accumulation simulation model is introduced,and the key parameters in the simulation model are *** addition,an experimental platform for a 100 kV spacer flashover test is *** flashover tests under superimposed voltage with opposing polarities are carried out,and the withstanding voltage of the spacer is ***,based on the proposed model,the threshold of the surface electric field strength(tangential component)on the DC spacer in SF_(6)/N_(2) mixed gases is *** a reliable insulation design of a DC GIS/GIL apparatus filled with 0.7 MPa SF_(6)/N_(2),the threshold of surface electric field strength on the DC spacer is 12 kV/*** insulation design rule can be referenced in the design of a high-voltage DC SF_(6)/N_(2)-filled GIS/GIL apparatus.

关键词： Charge accumulation DC spacer flashover voltage SF_(6)/N_(2) threshold of surface electric field strength

Intelligent overheating fault diagnosis for overhead transmission line using semantic segmentation

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High Voltage 2024年第2期9卷 309-318页

作者： Xiangyu Yang Youping tu Zhikang Yuan Zhong Zheng Geng Chen cong Wang Yan Xu Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijingChina College of Electronic and Information Engineering Tongji UniversityShanghaiChina

The strain clamps and leading wires are important components that connect conductors on overhead transmission lines and conduct *** operation,poor contact between these components can cause abnormal overheating,leading to electric failures and threatening power system ***,the use of unmanned aerial vehicles equipped with infrared thermal imagers for strain clamp and leading wire maintenance has become increasingly *** learning-based image recognition shows promising prospects for intelligent fault diagnosis of overheating faults.A pre-treatment method is proposed based on dynamic histogram equalisation to enhance the contrast of infrared *** DeepLab v3+network,loss function,and existing networks with different backbones are *** DeepLab v3+network with ResNet101 and convolutional block attention module added,and the Focal Loss function achieved the highest performance with an average pixel accuracy of 0.614,an average intersection over union(AIoU)of 0.567,an F1 score of 0.644,and a frequency weighted intersection over union of 0.594 on the test *** optimised Atrous rates has increased the AIoU by 12.91%.Moreover,an intelligent diagnosis scheme for evaluating the defect state of the strain clamps and leading wires is proposed and which achieves a diagnostic accuracy of 91.0%.

关键词： union fault diagnosis

Stndy on Transfer of Ni in Soil-Plant System Using ￣(63)NiTracer Method

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Pedosphere 1994年第3期4卷 273-278页

作者： tu cong(College of Resources and Environment, Southwest Agricultnrul University, Chongqing 620716(China))

study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Niand declined as time increased. The mobility was greater for soluble plus exchangeable fraction of soil Nibut very smaller for residual and Fe/Mn oxide bound fractions. These indicated that Ni was more mobileand more harmful in soils with a low pH and/or low content of Fe/Mn oxides.

关键词： i soil-plant system tracer technique transfer

Speciation and fractionation of heavy metals in soil experimentally contaminated with Pb, Cd, Cu and Zn together and effects on soil negative surface charge

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Journal of Environmental Sciences 2002年第4期14卷 439-444页

作者： ZHOU Dong mei, HAO Xiu zhen, tu cong, CHEN Huai man, SI You bin (Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. )

Speciation and fractionation of heavy metals in soil subsamples experimentally loaded with Pb, Cd, Cu and Zn in orthogonal design was investigated by sequential extraction, and operationally defined as water soluble and exchangeable(SE), weakly specific adsorbed(WSA), Fe and Mn oxides bound(OX) and organic bound(ORG). The results showed that fractions of heavy metals in the soil subsamples depended on their speciation. About 90% of Cd and 75% of Zn existed in soil subsamples in the SE fraction. Lead and Cu existed in soil subsamples as SE, WSA and OX fractions simultaneously, although SE was still the major fraction. Organic bound heavy metals were not clearly apparent in all the soil subsamples. The concentration of some heavy metal fractions in soil subsamples showed the good correlation with ionic impulsion of soil, especially for the SE fraction. Continuous saturation of soil subsamples with 0.20 mol/L NH 4Cl, which is the first step for determination of the negative surface charge of soil by the ion retention method, resulted in desorption of certain heavy metals from the soil. It was found that the percentage desorption of heavy metals from soil subsamples depended greatly on pH, the composition and original heavy metal content of the soil subsamples. However, most of the heavy metals in the soil subsamples were still be retained after multiple saturation. Compared with the parent soil, the negative surface charge of soil subsamples loaded with heavy metals did not show difference significantly from that of the parent one by statistical analysis. Heavy metals existed in the soil subsamples mainly as exchangeable and precipitated simultaneously.

关键词： soil heavy metals speciation soil surface charge

Enhanced allelopathy and competitive ability of invasive plant Solidago canadensis in its introduced range

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Journal of Plant Ecology 2013年第3期6卷 253-263页

作者： Yongge Yuan Bing Wang Shanshan Zhang Jianjun Tang cong tu Shuijin Hu Jean W.H.Yong Xin Chen College of Life Sciences Zhejiang UniversityHangzhou 310058China Department of Plant Pathogen North Carolina State UniversityRaleighNC 27695USA Singapore University of Technology and Design 279623 Singapore Yunnan Academy of Forestry Kunming 650200China

Aims Why invasive plants are more competitive in their introduced range than native range is still an unanswered question in plant invasion ***,we used the model invasive plant Solidago canaden-sis to test a hypothesis that enhanced production of allelopathic compounds results in greater competitive ability of invasive plants in the invaded range rather than in the native *** also exam-ined the degree to which the allelopathy contributes increased com-petitive ability of *** in the invaded *** We compared allelochemical production by *** growing in its native area(the USA)and invaded area(China)and also by populations that were collected from the two countries and grown together in a'common garden'greenhouse *** also tested the allelopathic effects of *** collected from either the USA or China on the germination of Kummerowia striata(a native plant in China).Finally,we conducted a common garden,greenhouse experiment in which *** was grown in monocul-ture or with *** from the USA or China to test the effects of allopathy on plant-plant competition with suitable controls such as adding activated carbon to the soil to absorb the allelochemicals and thereby eliminating any corresponding allopathic *** findings Allelochemical contents(total phenolics,total flavones and total saponins)and allelopathic effects were greater in *** sampled from China than those from the USA as demonstrated in a field survey and a common garden *** of ***-ata germination using *** extracts or previously grown in soil was greater using samples from China than from the *** competitive ability of *** against *** was also greater for plants originating from China than those from the *** could explain about 46%of the *** find-ings demonstrated that *** has evolved to be more allelo-pathic and competitive in the introdu

关键词： allelopathy biogeographical approach common garden experiment competition invasion speciesreceived

Study on the Correlation between 137Cs Loss and Soil Erosion in Central Highlands of Vietnam

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Journal of Environmental Science and Engineering(A) 2014年第2期3卷 117-122页

作者： Trinh cong tu Phan Son Hai Central Highlands Soils Fertilizers and Environment Research Center Buon Ma Thuot 55999 Vietnam Nuclear Research Institute Dalat 61999 Vietnam

Isotope of 137Cs appeared in the environment by nuclear weapon tests in the atmosphere in the 1950s and 1960s. When the 137Cs deposited to the ground, they were absorbed strongly and quickly by exchanging positions with other elements, and it had no ability to decompose in most of the environments. Redistribution of this isotope after settled down into the soil mainly occurs due to redistribution of soil surface. Research on the correlation between 137Cs loss and soil erosion was done in 2009, at 24 sites, on basaltic soil with slopes of 20%-25%. Statistical analysis by linear regression of experimental data according to equation ofy = a × xb got coefficients of a and b. They are 20.123 and 1.0967, respectively. The correlation ofy = 20.123 × x1.0967 was tested with error of 7.3%-35.8% between the actual soil loss and calculating. This correlation was applied to evaluate soil erosion rates in two catchments of Buon Yong and Ea Kao belonging to Dak Lak province, thereby giving soil erosion rates ranging from 3.44 t-ha-1 to 26.38 t-ha-1, depending on the conditions of sloping land and cover crops.

关键词： Catchment isotope of 137Cs soil erosion standardization.

Effect of Heavy Metals on Phosphorus Retention by Typic Udic Ferrisols: Equilibrium and Kinetics

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Pedosphere 2002年第1期12卷 15-24页

作者： tu cong, ZHENG CHUNRONG and CHEN HUAIMAN LMCP, Institute of Soil Science, the Chinese Academy of Sciences, P.O. Box 821, Nanjing 210008 (China) Department of Plant Pathology North Carolina State University P.O. Box 7616 RaleighNC 27695-7616 USA 中科院南京土壤所 LMCP CAS Nanjing 210008

A study was conducted to examine the effect of heavy metals (Cu,Pb, Zn and Cd in combination or alone) on the equilibrium andkinetics of phosphorus (P) retention in typic udic ferrisols by usingboth equilibrium and flow techniques. Fourteen soil samples withvarying artificial contamination of Cu, Pb, Zn and Cd were *** metal pollution led to increases in retention capacity andmaximum buffering capacity (MBC) of soil P. The rate of P retentionwas also increased and the time to reach equilibrium was advanced byheavy metals addition.

关键词： equilibrium kinetics heavy metlas phosphorus retention