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Journal of Forestry Research 2022年第3期33卷 899-909页

作者： bo Peng Jiawei Zhang jian Xing Jiuqing Liu Northeast Forestry University Harbin150040People’s Republic of China

The moisture content of dead forest fuel is an important indicator of risk levels of forest fires and prediction of fire spread. Moisture distribution is important to determine wild fire rating. However, it is often difficult to predict moisture distribution because of a complex terrain, changeable environments and low cover of commercial communication signals inside the forest. This study proposes a moisture content prediction system composed of environmental data collected using a long range radio frequency band 433 MHz wireless sensor network and data processing for moisture prediction based on a BP (back-propagation) neural network. In the fall of 2019, twenty nodes for the collection of environmental data were placed in four forest stands of Maoershan National Forest for a month;7440 sets of data including temperature, humidity, wind speed and air pressure were obtained. Half the data were used as a training set, the other as a testing set for a BP neural network. The results show that the average absolute error between the predicted value and the real value of moisture content of fuels of Larix gmelini, Betula platyphylla, Juglans mandshurica, and Quercus mongolica stands was 0.94%, 0.21%, 0.86%, 0.97%, respectively. The prediction accuracy was relatively high. The proposed distributed moisture content prediction method has the advantages of wide coverage and good real-time performance;at the same time, it is not limited by commercial signals and so it is especially suitable for forest fire prediction in remote mountainous areas.

关键词： Distributed moisture content prediction Dead fuel BP neural network

Predictions of nuclear charge radii based on the convolutional neural network

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Nuclear Science and Techniques 2023年第10期34卷 83-90页

作者： Ying-Yu Cao jian-You Guo bo Zhou Key Laboratory of Nuclear Physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Physics and Optoelectronics Engineering Anhui UniversityHefei 230601China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China

In this study, we developed a neural network that incorporates a fully connected layer with a convolutional layer to predict the nuclear charge radii based on the relationships between four local nuclear charge radii. The convolutional neural network(CNN) combines the isospin and pairing effects to describe the charge radii of nuclei with A ≥ 39 and Z ≥ 20. The developed neural network achieved a root mean square(RMS) deviation of 0.0195 fm for a dataset with 928 nuclei. Specifically, the CNN reproduced the trend of the inverted parabolic behavior and odd–even staggering observed in the calcium isotopic chain, demonstrating reliable predictive capability.

关键词： Nuclear charge radii Machine learning Neural network

Mechanism of Mg2+ dissolution from olivine and serpentine: Implication for bioleaching of high-magnesium nickel sulfide ore at elevated pH

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1069-1079页

作者： jian-zhi Sun jian-kang Wen bo-wei chen Biao Wu National Engineering Laboratory of Biohydrometallurgy GRINM Group Corporation Limited

To inhibit the dissolution of Mg^2+ during the bioleaching process of high-magnesium nickel sulfide ore, the effect of major bioleaching factors on the dissolution of Mg^2+ from olivine and serpentine was investigated and kinetics studies were carried out. The results indicated that the dissolution rate-controlling steps are chemical reaction for olivine and internal diffusion for serpentine. The most influential factor on the dissolution of Mg^2+ from olivine and serpentine was temperature, followed by p H and particle size. A novel method of bioleaching at elevated pH was used in the bioleaching of Jinchuan ore. The results showed that elevated pH could significantly reduce the dissolution of Mg^2+ and acid consumption along with slightly influencing the leaching efficiencies of nickel and cobalt. A model was used to explain the leaching behaviors of high-magnesium nickel sulfide ore in different bioleaching systems. The model suggested that olivine will be depleted eventually, whereas serpentine will remain because of the difference in the rate-controlling steps. Bioleaching at elevated pH is a suitable method for treating high-magnesium nickel sulfide ores.

关键词： olivine serpentine high-magnesium nickel sulfide ore bioleaching shrinking core model elevated pH

Storage life prediction under pre-strained thermally-accelerated aging of HTPB coating using the change of crosslinking density

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Defence Technology（防务技术） 2021年第4期17卷 1387-1394页

作者： Yong-qiang Du jian Zheng Gui-bo Yu Shijiazhuang Campus Army Engineering UniversityShijiazhuang050003China

In order to predict the storage life of a certain type of HTPB(hydroyl-terminated polybutadiene)coating at 25℃ and analyze the influence of pre-strain on the storage life,the accelerated aging tests of HTPB coating at 40℃,50℃,60℃,70℃ with the pre-strain of 0%,3%,6%,9%,respectively were carried *** variation regularity of the change of crosslinking density was analyzed and the aging model of HTPB coating under pre-strained thermally-accelerated aging was *** storage life of HTPB coating at 25℃ was estimated by using the Berthelot equation as the end point of the aging life with a 30% decrease in maximum *** results showed that the change of crosslinking density of HTPB coating increased with the increase of aging temperature and aging time,and decreased with the increase of *** 0% prestrain,the relationship between the change of crosslinking density of HTPB coating and the aging time can be described by the logarithmic model with the confidence probability greater than 99%.The stress relaxation phenomenon existed under 3%,6%and 9%pre-strained *** aging model considering chemical aging and pre-strain was established with the confidence probability greater than 90%.The storage life of HTPB coating was 15.2935 years at 25C under 0% prestrain,which was reduced by 13.9007%,75.6949% and 89.7859% under 3%,6% and 9% pre-strain,*** existence of pre-strain has a serious impact on the storage life of HTPB coating,therefore,the pre-strain should be avoided as much as possible during the actual storage.

关键词： HTPB coating Crosslinking density Aging model Storage life prediction Berthelot

Evaluating the performance and influencing factors of three portable black carbon monitors for field measurement

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Journal of Environmental Sciences 2024年第5期139卷 320-333页

作者： Liqing Wu Yicheng Shen Fei che Yuzhe Zhang jian Gao Chong Wang State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Jinan Ecological Environmental Protection Grid-Based Supervision Center Jinan 250013China

Black carbon(BC)is associated with adverse human health and climate *** BC spatial distribution imperatively requires low-cost and portable *** portable BC monitors are commercially available,but their accuracy and reliability are not always satisfactory during continuous field *** study evaluated three models of portable black carbon monitors,C12,MA350 and DST,and investigates the factors that affect their *** monitors were tested in urban Beijing,where portable devices running for one month alongside a regular-size reference aethalometer *** study considers several factors that could influence the monitors'performance,including ambient weather,aerosol composition,loading artifacts,and built-in *** results show that MA350and DST present considerable discrepancies to the reference instrument,mainly occurring at lower concentrations(0-500 ng/m^(3))and higher concentrations(2500-8000 ng/m^(3)),*** discrepancies were likely caused by the anomalous noise of MA350 and the loading artifacts of *** study also suggests that the ambient environment has limited influence on the monitors'performance,but loading artifacts and accompanying compensation algorithms can result in unrealistic *** on the evaluation,the study suggests that C12 is the best choice for unsupervised field measurement,DST should be used in scenarios where frequent maintenance is available,and MA350 is suitable for research purposes with post-processing *** study highlights the importance of assigning portable BC monitors to appropriate applications and the need for optimized real-time compensation algorithms.

关键词： Black carbon Aethalometer Loading artifact Performance evaluation Portable device

Pressure characteristics of landslide-generated impulse waves

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Journal of Mountain Science 2019年第8期16卷 1774-1787页

作者： TAN jian-min HUANG bo-lin ZHAO Yong-bo Wuhan Center of China Geological Survey WuhanChina433002 Hubei Key laboratory of Disaster Prevention and Mitigation China Three Gorges UniversityYichangChina443000

The destructiveness of impulse waves generated by landslides(IWL) originates from the wave’s movement and load, wherein the impulse wave’s load is the major cause of sub-aerial building damage and casualties. In this study, an experiment involving 16 groups of physical tests for the wave pressure generated by a landslide was designed, consisting of 4 sets of IWL and 4 opposite bank slope angles. A high-frequency strain system was used to measure the total pressure of the impulse wave in a water tank. The tests showed that the dynamic pressure caused by the IWL can be divided into two types: impact pressure generated by the jetflow and the pulsating pressure caused by the wave. Under the same impulse wave conditions, the maximum run-up becomes smaller as the opposite bank’s slope angle increases, and the jetflow maximum impact pressure experienced by the opposite bank increases, while the maximum pulsating pressure caused by the impulse wave is slightly decreased. Different from previous studies, the spatial maximum pressure distributions of the wave generated by landslide were concluded that the position of the maximum pulsating pressure appears adjacent to the still water surface, and the overall spatial distribution pattern of maximum wave pressure is presented as an inclined 'M' ***, this study is the first to quantitatively analyzed that impact pressure has a very short action time, is even 7 times of the pulse pressure value, and there is a simple mathematical linear relationship between the two. Currently, some wave-load formulas for wind waves and tides are not applicable to calculating the loads of IWL. Research on the load of IWL will explain the hazard of impulse wave very clearly, and will greatly contribute to hazard prevention, mitigation and risk assessment work associated with IWL.

关键词： Landslide Impulse wave Wave pressure Impact pressure Pulsating pressure Pressure distribution

Crop water stress index for off-season greenhouse green peppers in Liaoning, China

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International Journal of Agricultural and Biological Engineering 2014年第3期7卷 28-35页

作者： Li bo Wang Tieliang Sun jian College of Water Conservancy Shenyang Agricultural UniversityShenyang110866China

The crop water stress index(CWSI)is a complex instrument to effectively monitor the degree of water stress of crops and provides guidance for timely *** an experiment utilizing the CWSI with off-season green peppers planted in barrels in a greenhouse in Liaoning Province,Northeast China,this study monitors the sub-indexes--such as canopy temperature,environmental factors and yield--determines the changing law of each constituent,achieves an empirical model as well as a baseline formula for the canopy temperature of the peppers with a sufficient water supply,and verifies the rationality of the formula with corresponding experimental *** results obtained by using the CWSI show that the optimal time to determine the water deficit for off-season green peppers is at noon,by measuring the diurnal variation in the peppers with different water *** is a nonlinear relationship between the yield and the average CWSI at the prime fruit-bearing period;moreover,the optimal time to supply water for off-season green peppers comes when the average water stress index ranges between 0.2 and 0.4 during the prime fruiting stage,thereby ensuring a high yield.

关键词： crop water stress index off-season green peppers in greenhouse high yield canopy temperature irrigation water deficit

Complete Hypersurfaces with Constant Laguerre Scalar Curvature in R^n

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Acta Mathematica Sinica,English Series 2016年第6期32卷 715-724页

作者： jian bo FANG Feng jiang LI School of Mathematics and Statistics Chuxiong Normal University Department of Mathematics Yunnan Normal University

Let x ： M^n-1→ R^n be an umbilical free hypersurface with non-zero principal curvatures. Two basic invariants of M under the Laguerre transformation group of Rn are Laguerre form C and Laguerre tensor L. In this paper, we prove the following theorem： Let M be an （n-1）-dimensional （n 〉 3） complete hypersurface with vanishing Laguerre form and with constant Laguerre scalar curvature R in R^n, denote the trace-free Laguerre tensor by L = L -1/n-1tr（L）· Id. If supM ｜｜L｜｜=0,then M is Laguerre equivalent to a Laguerre isotropic hypersurface; and if supM ｜｜L^-｜｜≡√（n-1）（n-2）R/ （n-1）（n-2）（n-3） , M isLaguerre equivalent to the hypersurface x^- ： H^1× S^n-2 → R^n.

关键词： Laguerre isoparametric hypersurface Laguerre second fundamental form Laguerre metric Laguerre form parallel Laguerre form

Secondary Precipitation Behavior of Nitride in the Electro-slag Remelted Structure of Alloy 690

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Acta Metallurgica Sinica(English Letters) 2017年第8期30卷 771-780页

作者： Min Wang bo chen Xian-Chao Hao Ying-che Ma Kui Liu Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The precipitation and evolution of secondary nitrides （S-nitrides） in the Alloy 690 electro-slag remelted （ESR） structure were investigated. Experimental results indicate that S-nitrides precipitated in the interdendritic region of the ESR structure at temperatures higher than 1100 ℃. S-nitrides could spread throughout the entire interdendritic area after sufficient exposure, and they were more numerous and much finer than primary nitrides. Furthermore, after studying the evolution of S-nitride particles at 1100, 1200 and 1300℃, it was determined that the precipitation of S-nitrides was controlled by the diffusion of nitrogen. In addition, by investigating the elemental segregation of ESR structure and calculating critical Ti concentrations, S-nitride precipitation was found to be thermodynamically inevitable in the Alloy 690 ESR structure.

关键词： Alloy 690 ESR Nitride Precipitation

Generalized system for strongly g-r-pseudomonotonic nonlinear variational inequalities in Hilbert spaces

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Applied Mathematics(A Journal of Chinese Universities) 2010年第1期25卷 63-68页

作者： YANG Xin-bo PENG jian-wen Department of Computer Science Chongqing Education College Chongqing 400067 China College of Mathematics and Computer Science Chongqing Normal University Chongqing 400047China

The approximation solvability of a generalized system for strongly g-r- pseudomonotonic nonlinear variational inequalities in Hilbert spaces is studied based on the convergence of the projection method. The results pr... 详细信息

关键词： Projection method strong g-r-pseudomonotonicity variational inequality convergence.