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Impact of fertilization on chestnut growth, N and P concentrations in runoff water on degraded slope land in South China

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Journal of Environmental Sciences 2007年第7期19卷 827-833页

作者： zeng shu-cai CHEN Bei-guang JIANG Cheng-ai WU Qi-tang College of Forestry South China Agricultural University Guangzhou 510642 China College of Natural Resources and Environment South China Agricultural University Guangzhou 510642 China

Growing fruit trees on the slopes of rolling hills in South China was causing serious environmental problems because of heavy application of chemical fertilizers and soil erosion. Suitable sources of fertilizers and proper rates of applications were of key importance to both crop yields and environmental protection. In this article, the impact of four fertilizers, i.e., inorganic compound fertilizer, organic compound fertilizer, pig manure compost, and peanut cake （peanut oil pressing residue）, on chestnut （Castanea mollissima Blume） growth on a slope in South China, and on the total N and total P concentrations in runoff waters have been investigated during two years of study, with an orthogonal experimental design. Results show that the organic compound fertilizer and peanut cake promote the heights of young chestnut trees compared to the control. In addition, peanut cake increases single-fruit weights and organic compound fertilizer raises single-seed weights. All the fertilizers increased the concentrations of total N and total P in runoff waters, except for organic compound fertilizer, in the first year experiment. The observed mean concentrations of total N varied from 1.6 mg/L to 3.2 mg/L and P from 0.12 mg/L to 0.22 mg/L, which were increased with the amount of fertilizer applications, with no pattern of direct proportion. On the basis of these experiment results, organic compound fertilizer at 2 kg/tree and peanut cake at 1 kg/tree are recommended to maximize chestnut growth and minimize water pollution.

关键词： chestnut fertilization N concentration P concentration runoff water South China

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A COUPLED METHOD COMBINING CROUZEIX-RAVIART NONCONFORMING AND NODE CONFORMING FINITE ELEMENT SPACES FOR BOIT CONSOLIDATION MODEL

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Journal of Computational Mathematics 2024年第4期42卷 911-931页

作者： Yuping zeng Mingchao cai Liuqiang Zhong School of Mathematics Jiaying UniversityMeizhou 514015China Department of Mathematics Morgan State University1700 E Cold Spring LnBaltimoreMD 21251USA School of Mathematical Science South China Normal UniversityGuangzhou 520631China

A mixed finite element method is presented for the Biot consolidation problem in *** precisely,the displacement is approximated by using the Crouzeix-Raviart nonconforming finite elements,while the fuid pressure is approximated by using the node conforming finite *** well-posedness of the fully discrete scheme is established,and a corresponding priori error estimate with optimal order in the energy norm is also *** experiments are provided to validate the theoretical results.

关键词： Poroelasticity Nonconforming finite element Inf-sup condition A priori error estimate

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Nitrogen and Phosphorus Runoff Losses from Orchard Soils in South China as Affected by Fertilization Depths and Rates

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Pedosphere 2008年第1期18卷 45-53页

作者： zeng shu-cai SU Zhi-Yao CHEN Bei-Guang WU Qi-Tang OUYANG Ying College of Forestry South China Agricultural University Guangzhou 510642 (China) College of Natural Resources and Environment South China Agricultural University Guangzhou 510642 (China) Department of Water Resources St. Johns River Water Management District P.O. Box 1429 Palatka FL 32178-1429 (USA)

Fertilizers are heavily applied in orchards of the hilly and mountainous topography of South China and may increase nutrient loadings to receiving waters.A simple runoff collecting system was used to measure the effects of different fertilization treatments on total N and P concentrations of surface runoff in a Chinese chestnut (Castanea mollissima Blume) orchard in Dongyuan County,Guangdong Province,*** such orchards,fertilizer was typically applied in two short furrows or pits on either side of each *** included three application depths (surface,10cm and 20 cm),and three application rates (low,median and high).Results showed that 90.5% of the runoff water samples had a total N concentration higher than 0.35 mgL^(-1) and 54.2% had a total P concentration higher than 0.1 mgL^(-1).Fertilizer application at all depths and at all but the lowest rate significantly increased total N and P concentrations in runoff *** with chemical compound fertilizer at a soil depth of 20cm produced significantly lower (P<0.05) total N concentration in runoff than both surface and 10-cm depth fertilization,and significantly lower (P<0.05) total P concentration in runoff than surface *** N and P concentrations in runoff significantly increased with the application rate of organic *** the exception of total P concentrations,which were not significantly different between the control and fertilization at a rate of 119 kg P ha-1 in organic form,all the other fertilization treatments produced significantly higher total N and total P concentrations in runoff than the control.A fertilization depth≥20cm and an application rate≤72 kg N ha^(-1) or 119 kg P ha^(-1) for compound organic fertilizer was suggested to substantially reduce N and P runoff losses from hillslope orchards and to protect receiving waters in South China.

关键词： fertilization depth fertilization rate runoff total N total P

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Towards complex scenes: A deep learning-based camouflaged people detection method for snapshot multispectral images

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Defence Technology（防务技术） 2024年第4期34卷 269-281页

作者： shu Wang Dawei zeng Yixuan Xu Gonghan Yang Feng Huang Liqiong Chen School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

Camouflaged people are extremely expert in actively concealing themselves by effectively utilizing cover and the surrounding environment. Despite advancements in optical detection capabilities through imaging systems, including spectral, polarization, and infrared technologies, there is still a lack of effective real-time method for accurately detecting small-size and high-efficient camouflaged people in complex real-world scenes. Here, this study proposes a snapshot multispectral image-based camouflaged detection model, multispectral YOLO(MS-YOLO), which utilizes the SPD-Conv and Sim AM modules to effectively represent targets and suppress background interference by exploiting the spatial-spectral target information. Besides, the study constructs the first real-shot multispectral camouflaged people dataset(MSCPD), which encompasses diverse scenes, target scales, and attitudes. To minimize information redundancy, MS-YOLO selects an optimal subset of 12 bands with strong feature representation and minimal inter-band correlation as input. Through experiments on the MSCPD, MS-YOLO achieves a mean Average Precision of 94.31% and real-time detection at 65 frames per second, which confirms the effectiveness and efficiency of our method in detecting camouflaged people in various typical desert and forest scenes. Our approach offers valuable support to improve the perception capabilities of unmanned aerial vehicles in detecting enemy forces and rescuing personnel in battlefield.

关键词： Camouflaged people detection Snapshot multispectral imaging Optimal band selection MS-YOLO Complex remote sensing scenes

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Study on trifluoromethanesulfonic acid-promoted synthesis of daidzein: Process optimization and reaction mechanism

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Chinese Journal of Chemical Engineering 2024年第7期71卷 132-139页

作者： Hai Cao Haibin Yang Yanxiong Fang Yuandi zeng Xiaolan cai Jingjing Ma School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Daidzein has been widely used in pharmaceuticals,nutraceuticals,cosmetics,feed additives,*** preparation process and related reaction mechanism need to be further investigated.A cost-effective process for synthesizing daidzein was developed in this *** this article,a two-step synthesis of daidzein(Friedel–Crafts acylation and[5+1]cyclization)was developed via the employment of trifluoromethanesulfonic acid(TfOH)as an effective promoting *** effect of reaction conditions such as solvent,the amount of TfOH,reaction temperature,and reactant ratio on the conversion rate and the yield of the reaction,respectively,was systematically investigated,and daidzein was obtained in 74.0%isolated yield under optimal *** to the facilitating effect of TfOH,the Friedel–Crafts acylation was completed within 10 min at 90℃ and the[5+1]cyclization was completed within 180 min at 25℃.In addition,a possible reaction mechanism for this process was *** results of the study may provide useful guidance for industrial production of daidzein on a large scale.

关键词： Synthesis Optimal design Chemical processes Reaction mechanism

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华南赤红壤无机复合肥氮磷淋失特征

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应用生态学报 2007年第5期18卷 1015-1020页

作者：曾曙才吴启堂华南农业大学林学院广州510642 华南农业大学资源环境学院广州510642

采用室内土柱淋溶模拟试验,研究了不同施肥水平下无机复合肥中氮和磷在华南赤红壤中的淋失特征.结果表明：铵态氮、硝态氮和总氮淋失量均随施肥量增加而提高;肥料中氮的淋失率在36.8%～49.2%之间,总氮淋失量（y）与施肥量（x）之间的... 详细信息

采用室内土柱淋溶模拟试验,研究了不同施肥水平下无机复合肥中氮和磷在华南赤红壤中的淋失特征.结果表明：铵态氮、硝态氮和总氮淋失量均随施肥量增加而提高;肥料中氮的淋失率在36.8%～49.2%之间,总氮淋失量（y）与施肥量（x）之间的回归方程为y=0.3667x＋66.483（R^2=0.992）;铵态氮和总氮的淋失主要集中在前5次淋洗,硝态氮的淋失持续时间更长.施肥量对可溶性磷淋失量无显著影响,但颗粒磷和总磷淋失量均随施肥量增加呈上升趋势;肥料磷淋失率在0.002%～0.010%之间,总磷淋失量（y）与施肥量（x）之间的回归方程为y=7e^-5x＋0.0538（R^2=0.931）;磷的淋失动态与氮显著不同,为缓慢的持续累积过程.硝态氮与铵态氮淋失量比值和可溶性磷与颗粒磷淋失量比值均随施肥量增加呈下降趋势.

关键词：无机复合肥赤红壤氮磷淋失

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A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

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Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： Zhi-Wei Shen shu-Feng Hu Chen zeng Wei-Qing Kong Mei-Fang Zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12/12 rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 30 min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree

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Advances in selective conversion of carbohydrates into 5-hydroxymethylfurfural

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Green Energy & Environment 2024年第9期9卷 1384-1406页

作者： Jie Liang Jianchun Jiang Tingting cai Chao Liu Jun Ye Xianhai zeng Kui Wang Institute of Chemical Industry of Forest Products Chinese Academy of Forestry National Engineering Lab.for Biomass Chemical Utilization Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry University College of Energy State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University

Converting carbohydrates into 5-hydroxymethylfurfural(5-HMF) is an attractive and promising route for value-added utilization of agricultural and forestry biomass resource. As an important platform compound, 5-HMF possesses high active furan structure with hydroxymethyl and aldehyde group for production of various bio-chemicals and materials, meanwhile, which suffer from low stability and poor yield during the industrial biorefinery process. Hence, selective production of 5-HMF with high-yield and low-cost has attracted extensive attention from scientific and industrial researchers. This review sorted and described the latest advanced research on solvent and catalyst system, as well as energy field effect for production of 5-HMF with different feedstock in detail, emphatically discussing the solvent effect and its synergistic effect with other aspects. Besides, the future prospects and challenges for production of 5-HMF from carbohydrates were also presented, which provide a profound insight into industrial 5-HMF process with economic and environmental feature.

关键词： 5-Hydroxymethylfurfural Biorefinery Solvent Selectivity Carbohydrate

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Modeling of multiphase flow in low permeability porous media:Effect of wettability and pore structure properties

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1127-1139页

作者： Xiangjie Qin Yuxuan Xia Juncheng Qiao Jiaheng Chen Jianhui zeng Jianchao cai National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China Research Institute of Petroleum Exploration and Development Beijing10083China

Multiphase flow in low permeability porous media is involved in numerous energy and environmental ***,a complete description of this process is challenging due to the limited modeling scale and the effects of complex pore structures and *** address this issue,based on the digital rock of low permeability sandstone,a direct numerical simulation is performed considering the interphase drag and boundary slip to clarify the microscopic water-oil displacement *** addition,a dual-porosity pore network model(PNM)is constructed to obtain the water-oil relative permeability of the *** displacement efficiency as a recovery process is assessed under different wetting and pore structure *** show that microscopic displacement mechanisms explain the corresponding macroscopic relative *** injected water breaks through the outlet earlier with a large mass flow,while thick oil films exist in rough hydrophobic surfaces and poorly connected *** variation of water-oil relative permeability is significant,and residual oil saturation is high in the oil-wet *** flooding is extensive,and the residual oil is trapped in complex pore networks for hydrophilic pore surfaces;thus,water relative permeability is lower in the water-wet *** the displacement efficiency is the worst in mixed-wetting systems for poor water *** negatively correlates with invading oil volume fraction due to strong capillary resistance,and a large microporosity corresponds to low residual oil *** work provides insights into the water-oil flow from different modeling perspectives and helps to optimize the development plan for enhanced recovery.

关键词： Low permeability porous media Water-oil flow Wettability Pore structures Dual porosity pore network model(PNM) Free surface model

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A spatiotemporal deep learning method for excavation-induced wall deflections

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3327-3338页

作者： Yuanqin Tao Shaoxiang zeng Honglei Sun Yuanqiang cai Jinzhang Zhang Xiaodong Pan College of Civil Engineering Zhejiang University of TechnologyHangzhou310023China Ministry of Education(MOE)Key Laboratory of Soft Soils and Geoenvironmental Engineering(SSGeo) Zhejiang UniversityHangzhou310058China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education and Department of Geotechnical Engineering Tongji UniversityShanghai200092China

Data-driven approaches such as neural networks are increasingly used for deep excavations due to the growing amount of available monitoring data in practical ***,most neural network models only use the data from a single monitoring point and neglect the spatial relationships between multiple monitoring ***,most models lack flexibility in providing predictions for multiple days after monitoring *** study proposes a sequence-to-sequence(seq2seq)two-dimensional(2D)convolutional long short-term memory neural network(S2SCL2D)for predicting the spatiotemporal wall deflections induced by deep *** model utilizes the data from all monitoring points on the entire wall and extracts spatiotemporal features from data by combining the 2D convolutional layers and long short-term memory(LSTM)*** S2SCL2D model achieves a long-term prediction of wall deflections through a recursive seq2seq *** excavation depth,which has a significant impact on wall deflections,is also considered using a feature fusion *** excavation project in Hangzhou,China,is used to illustrate the proposed *** results demonstrate that the S2SCL2D model has superior prediction accuracy and robustness than that of the LSTM and S2SCL1D(one-dimensional)*** prediction model demonstrates a strong generalizability when applied to an adjacent *** on the long-term prediction results,practitioners can plan and allocate resources in advance to address the potential engineering issues.

关键词： Braced excavation Wall deflections Deep learning Convolutional layer Long short-term memory(LSTM) Sequence to sequence(seq2seq)

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