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PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL SUSTAINABILITY IN NORTH-WEST CHINA

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期 doi: 10.15302/J-FASE -2020355

摘要：

Agriculture faces the dual challenges of food security and environmental sustainability. Here, we investigate current maize production at the field scale, analyze the yield gaps and impacting factors, and recommend measures for sustainably closing yield gaps. An experiment was conducted on a 3.9-ha maize seed production field in arid north-western China, managed with border and drip irrigation, respectively, in 2015 and 2016. The relative yield reached 70% in both years. However, drip irrigation saved 227 mm irrigation water during a drier growing season compared with traditional border irrigation, accounting for 44% of the maize evapotranspiration (ET). Yield variability under drip irrigation was 12.1%, lower than the 18.8% under border irrigation. Boundary line analysis indicates that a relative yield increase of 8% to 10% might be obtained by optimizing the yield-limiting factors. Plant density and soil available water content and available nitrogen were the three major factors involved. In conclusion, closing yield gaps with agricultural sustainability may be realized by optimizing agronomic, irrigation and fertilizer management, using water-saving irrigation methods and using site-specific management.

 

关键词： boundary line analysis     irrigation method     precision agriculture     spatial variability     yield gaps     yield-limiting factors    

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An improved artificial bee colony algorithm with MaxTF heuristic rule for two-sided assembly line balancing

Xiaokun DUAN, Bo WU, Youmin HU, Jie LIU, Jing XIONG

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 241-253 doi: 10.1007/s11465-018-0518-6

摘要： Two-sided assembly line is usually used for the assembly of large products such as cars, buses, and trucks. With the development of technical progress, the assembly line needs to be reconfigured and the cycle time of the line should be optimized to satisfy the new assembly process. Two-sided assembly line balancing with the objective of minimizing the cycle time is called TALBP-2. This paper proposes an improved artificial bee colony (IABC) algorithm with the MaxTF heuristic rule. In the heuristic initialization process, the MaxTF rule defines a new task’s priority weight. On the basis of priority weight, the assignment of tasks is reasonable and the quality of an initial solution is high. In the IABC algorithm, two neighborhood strategies are embedded to balance the exploitation and exploration abilities of the algorithm. The employed bees and onlooker bees produce neighboring solutions in different promising regions to accelerate the convergence rate. Furthermore, a well-designed random strategy of scout bees is developed to escape local optima. The experimental results demonstrate that the proposed MaxTF rule performs better than other heuristic rules, as it can find the best solution for all the 10 test cases. A comparison of the IABC algorithm and other algorithms proves the effectiveness of the proposed IABC algorithm. The results also denote that the IABC algorithm is efficient and stable in minimizing the cycle time for the TALBP-2, and it can find 20 new best solutions among 25 large-sized problem cases.

关键词： two-sided assembly line balancing problem     artificial bee colony algorithm     heuristic rules     time boundary    

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A new meshless approach for bending analysis of thin plates with arbitrary shapes and boundary conditions

《结构与土木工程前沿（英文）》 2022年 第16卷 第1期   页码 75-85 doi: 10.1007/s11709-021-0798-5

摘要： An efficient and meshfree approach is proposed for the bending analysis of thin plates. The approach is based on the choice of a set of interior points, for each of which a basis function can be defined. Plate deflection is then approximated as the linear combination of those basis functions. Unlike traditional meshless methods, present basis functions are defined in the whole domain and satisfy the governing differential equation for plate. Therefore, no domain integration is needed, while the unknown coefficients of deflection expression could be determined through boundary conditions by using a collocation point method. Both efficiency and accuracy of the approach are shown through numerical results of plates with arbitrary shapes and boundary conditions under various loads.

关键词： plate     bending     meshless method     collocation    

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Acoustic analysis of lightweight auto-body based on finite element method and boundary element method

LIANG Xinhua, ZHU Ping, LIN Zhongqin, ZHANG Yan

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 99-103 doi: 10.1007/s11465-007-0017-7

摘要： A lightweight automotive prototype using alternative materials and gauge thickness is studied by a numerical method. The noise, vibration, and harshness (NVH) performance is the main target of this study. In the range of 1 150 Hz, the frequency response function (FRF) of the body structure is calculated by a finite element method (FEM) to get the dynamic behavior of the auto-body structure. The pressure response of the interior acoustic domain is solved by a boundary element method (BEM). To find the most contributing panel to the inner sound pressure, the panel acoustic contribution analysis (PACA) is performed. Finally, the most contributing panel is located and the resulting structural optimization is found to be more efficient.

关键词： harshness     automotive prototype     structural optimization     vibration     efficient    

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Dynamic characteristics analysis of active constrained layer damping plate with various boundary conditions

Jing LU, Yu XIANG, Qiao NI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 449-455 doi: 10.1007/s11465-011-0240-0

摘要：

Considering the direct and converse piezoelectric effect, expressions of piezoelectric membrane internal forces in the piezoelectric constrained layer were given. The control equations of the piezoelectric constrained layer and host plate were obtained in according with the thin plate theory. Based on the layer wised principle, the integrated first order differential equation of an active constrained layer damping (ACLD) plate was derived for the simply supported boundary condition. Then, this method was expanded to the ACLD plate with cantilever boundary condition by virtue of geometric analogy method. Employing the extended homogeneous capacity precision integration approach, a high precision semi-analytical method was proposed to analyze the dynamic characteristics of the ACLD plate with various boundary conditions. The comparison with the literature results has verified the accuracy and effectiveness of the present method.

关键词： active constrained layer damping (ACLD) plate     dynamic characteristics     semi-analytical method     extended homogeneous capacity precision integration approach    

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PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL SUSTAINABILITY IN NORTH-WEST CHINA

Xiuwei GUO, Manoj Kumar SHUKLA, Di WU, Shichao CHEN, Donghao LI, Taisheng DU

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 525-544 doi: 10.15302/J-FASE-2020355

摘要： Agriculture faces the dual challenges of food security and environmental sustainability. Here, we investigate current maize production at the field scale, analyze the yield gaps and impacting factors, and recommend measures for sustainably closing yield gaps. An experiment was conducted on a 3.9-ha maize seed production field in arid north-west China, managed with border and drip irrigation, respectively, in 2015 and 2016. The relative yield reached 70% in both years. However, drip irrigation saved 227 mm irrigation water during a drier growing season compared with traditional border irrigation, accounting for 44% of the maize evapotranspiration (ET). Yield variability under drip irrigation was 12.1%, lower than the 18.8% under border irrigation. Boundary line analysis indicates that a relative yield increase of 8% to 10% might be obtained by optimizing the yield-limiting factors. Plant density and soil available water content and available nitrogen were the three major factors involved. In conclusion, closing yield gaps with agricultural sustainability may be realized by optimizing agronomic, irrigation and fertilizer management, using water-saving irrigation methods and using site-specific management.

关键词： boundary line analysis     irrigation method     precision agriculture     spatial variability     yield gaps     yield-limiting factors    

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Improved numerical method for time domain dynamic structure-foundation interaction analysis based onscaled boundary finite element method

DU Jianguo, LIN Gao

《结构与土木工程前沿（英文）》 2008年 第2卷 第4期   页码 336-342 doi: 10.1007/s11709-008-0054-2

摘要： Based on the reduced set of base function in scaled boundary finite element method (SBFEM), an improved time domain numerical approach for the dynamic structure-foundation interaction analysis was proposed. With reasonable choice of the number of base functions, the degrees of freedom on the structure-foundation interface were reduced and the associated computation for the calculation of convolution integral was greatly reduced. The results of this proposed approach applied to the calculation of a gravity dam and an arch dam. The acceleration frequency response functions were calculated and the influences affected by different reduced set of base functions as well as full set were compared. It was found that a higher degree of reduced set of base functions resulted in a significant increase of computational efficiency but a little bit of loss in accuracy. When the reduced set was decreased by 60%, the efficiency may be increased to up to five times, while the loss of accuracy of peak value of response will be less than 4%. It may be concluded that the proposed approach is suitable for large-scale structure-foundation interaction analysis.

关键词： structure-foundation interface     computational efficiency     different     suitable     numerical approach    

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Performance analysis for a two-way relaying power line networkwith analog network coding

Yu-wen QIAN,Meng TIAN,Xue JIANG,Hua-ju SONG,Feng SHU,Jun LI

《信息与电子工程前沿（英文）》 2015年 第16卷 第10期   页码 892-898 doi: 10.1631/FITEE.1500135

摘要： In this paper, we investigate a two-way relaying power line communication (PLC) network with analog network coding. We focus on the analysis of the system outage probability, symbol error rate, and average capacity. Specifically, we first derive the probability density function (PDF) of the received signal-to-noise ratio (SNR) with a closed form, by exploiting the statistical properties of the PLC channel. Then with the help of this PDF, we develop the outage probability, symbol error rate, and average capacity with closed forms, based on the Hermite polynomial. Simulations show that the derived analytical results are consistent with those by Monte Carlo simulation.

关键词： Power line communication     Outage probability     Symbol error rate     Signal attenuation    

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Conformal analysis of fundamental frequency of vibration of elastic clamped plates

QI Hongyuan, ZHU Hengjun

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 429-432 doi: 10.1007/s11465-007-0073-z

摘要： To calculate the fundamental frequency of vibration of special-shaped and elastic clamped plates, the conformal mapping theory is adopted to separate the interpolating points of a complicated boundary into odd and even sequences, both of which can be mutually iterated, so that the conformal mapping function between the complicated region and the unit dish region is established. Trigonometric interpolation and convergence along the normal direction methods are provided, and the complex coefficients of the conformal mapping function are calculated. Galerkin method is used to obtain the solution of fundamental frequency in the vibrating differential function of the complicated vibrating region. Finally, taking ellipse elastic clamped plates as an example, the effects on fundamental frequency coefficient caused by eccentric ratio and area size are analyzed.

关键词： direction     theory     vibration     odd     complicated boundary    

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压力梯度作用下相干结构的演化

陆利蓬,李兆瑞

《中国工程科学》 2002年 第4卷 第11期   页码 50-56

摘要：

采用共振三波的一个周期作为湍流边界层近壁区相干结构的初值，用直接数值模拟方法对有压力梯度，包括定常压力梯度和变压力梯度作用下相干结构的演化进行了研究，得出其各种特性的变化与实验观测到的结果一致。压力梯度对相干结构初始扰动波的选择以及演化过程都起作用，相比之下对前者的作用更大。条纹结构和流向涡之间有某种内在的紧密的联系，可能是产生流向涡的起因。

关键词： 相干结构     湍流边界层     压力梯度     直接数值模拟    

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Anlotinib as third- or further-line therapy for short-term relapsed small-cell lung cancer: subgroupanalysis of a randomized phase 2 study (ALTER1202)

《医学前沿（英文）》 2022年 第16卷 第5期   页码 766-772 doi: 10.1007/s11684-021-0916-8

摘要： Patients with small-cell lung cancer (SCLC) relapse within months after completing previous therapies. This study aimed to investigate the efficacy and safety of anlotinib as third- or further-line therapy in patients with short-term relapsed SCLC from ALTER1202. Patients with short-term relapsed SCLC (disease progression within 3 months after completing ≥ two lines of chemotherapy) in the anlotinib (n = 67) and placebo (n = 34) groups were analyzed. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival, objective response rate (ORR), disease control rate, and safety. Anlotinib significantly improved median PFS/OS (4.0 vs. 0.7 months, P < 0.0001)/(7.3 vs. 4.4 months, P = 0.006) compared with placebo. The ORR was 4.5%/2.9% in the anlotinib/placebo group (P = 1.000). The DCR in the anlotinib group was higher than that in the placebo group (73.1% vs. 11.8%, P < 0.001). The most common adverse events (AEs) were hypertension (38.8%), loss of appetite (28.4%), and fatigue (22.4%) in the anlotinib group and gamma-glutamyl transpeptidase elevation (20.6%) in the placebo group. No grade 5 AEs occurred. For patients with short-term relapsed SCLC, third- or further-line anlotinib treatment was associated with improved survival benefit. Further studies are warranted in this regard.

关键词： anlotinib     chemotherapy     short-term relapsed     small-cell lung cancer    

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Development and case study of a new-generationmodel-VAT for analyzing the boundary conditions influence

Wenwei Yang, Yun Zhu, Carey Jang, Shicheng Long, Che-Jen Lin, Bin Yu, Zachariah Adelman, Shuxiao Wang, Jia Xing, Long Wang, Jiabin Li

《环境科学与工程前沿（英文）》 2018年 第12卷 第1期 doi: 10.1007/s11783-018-1010-6

摘要： Atmospheric models are essential tools to study the behaviorof air pollutants. To interpret the complicated atmospheric modelsimulations, a new-generation Model Visualization and Analysis Tool(Model-VAT) has been developed for scientists to analyze the modeldata and visualize the simulation results. The Model-VAT incorporatesanalytic functions of conventional tools and enhanced capabilitiesin flexibly accessing, analyzing, and comparing simulated resultsfrom multi-scale models with different map projections and grid resolutions.The performance of the Model-VAT is demonstrated by a case study ofinvestigating the influence of boundary conditions (BCs) on the ambientHg formation and transport simulated by the CMAQ model over the PearlRiver Delta (PRD) region. The alternative BC options are taken from(1) default time-independent profiles, (2) outputs from a CMAQ simulationof a larger nesting domain, and (3) concentration files from GEOS-Chem(re-gridded and re-projected using the Model-VAT). The three BC inputsand simulated ambient concentrations and deposition were comparedusing the Model-VAT. The results show that the model simulations basedon the static BCs (default profile) underestimates the Hg concentrationsby ~6.5%, dry depositions by ~9.4%, and wet depositions by ~43.2%compared to those of the model-derived (e.g. GEOS-Chem or nestingCMAQ) BCs. This study highlights the importance of model nesting approachand demonstrates that the innovative functions of Model-VAT enhancesthe efficiency of analyzing and comparing the model results from variousatmospheric model simulations.

关键词： Model and data visualization     Model and data analysis     CMAQ     Boundary conditions     Mercury    

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Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 385-391 doi: 10.1007/s11705-011-1101-4

摘要： This paper presents the distribution of a solute undergoing a first order chemical reaction in an axisymmetric laminar boundary layer flow along a stretching cylinder. Velocity slip condition at the boundary is used instead of no-slip condition. Similarity transformations are used to convert the partial differential equations corresponding to momentum and concentration into highly nonlinear ordinary differential equations. Numerical solutions of these equations are obtained by the shooting method. The velocity decreases with increasing slip parameter. The skin friction as well as the mass transfer rate at the surface is larger for a cylinder than for a flat plate.

关键词： boundary layer     stretching cylinder     partial slip     mass transfer     similarity solution    

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Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 235-240 doi: 10.1007/s11465-017-0458-6

摘要： We describe the formation of nested wrinkles created by the thermal mismatch between a narrow-band thin film and a compliant substrate. When a film is described as “narrow-band”, it literally means that the film band width is much shorter than its length; more precisely, it means that the width is comparable with the wavelength of the wrinkles. A silicon mask was used during film sputtering to create narrow-band films on poly (dimethylsiloxane) substrate, thus creating regular boundaries to steer local stresses and control wrinkle morphology. Disordered nano-scale wrinkles were found nested within highly ordered micro-scale sinusoidal wrinkles. The formation of nested wrinkles was explained through the amplitude and wavelength saturation of nano-scale wrinkles. The disordered morphology of nano-scale wrinkles and the highly ordered morphology of micro-scale wrinkles were explained by using the boundary effect.

关键词： nested and hierarchical wrinkles     morphology     amplitude saturation     boundary effect    

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Evaluation of automated in-line precision dairy farming technology implementation in three dairy farms

Maria CARIA, Giuseppe TODDE, Antonio PAZZONA

《农业科学与工程前沿（英文）》 2019年 第6卷 第2期   页码 181-187 doi: 10.15302/J-FASE-2019252

摘要：

In recent decades, dairy farms have been exposed to wide variation in profit levels due to a considerable variability of milk price, and energy and feed costs. Consequently, it is necessary for the dairy industry to improve efficiency and productivity by adopting innovative technologies. The automated in-parlour milk analysis and separation is mainly useful to produce low or high quality milk and to monitor the animal health status. Milk with high levels of protein and fat contents may reduce the intensity of standardization during cheesemaking process, reducing production costs. The study aimed to evaluate the efficiency of real-time milk separation during milking and the performance of the milking machine after implementation of AfiMilk MCS. In addition, the economic aspects were assessed. The separation of milk required the existing milking parlors to be equipped with an additional milkline to allow channeling milk with low and high coagulation properties into two different cooling tanks. The results showed that the high coagulation milk fraction, compared to the bulk milk, increased in fat (from 18% to 43%) and protein (from 3% to 7%) concentration. The technology tested has given promising results showing reliability and efficiency in milk separation in real time with affordable implementation costs.

关键词： cheese yield     infrared analysis     milk quality     real-time measurement     sensor    

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标题 作者 时间 类型 操作

PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL SUSTAINABILITY IN NORTH-WEST CHINA

期刊论文

An improved artificial bee colony algorithm with MaxTF heuristic rule for two-sided assembly line balancing

Xiaokun DUAN, Bo WU, Youmin HU, Jie LIU, Jing XIONG

期刊论文

A new meshless approach for bending analysis of thin plates with arbitrary shapes and boundary conditions

期刊论文

Acoustic analysis of lightweight auto-body based on finite element method and boundary element method

LIANG Xinhua, ZHU Ping, LIN Zhongqin, ZHANG Yan

期刊论文

Dynamic characteristics analysis of active constrained layer damping plate with various boundary conditions

Jing LU, Yu XIANG, Qiao NI

期刊论文

PLANT DENSITY, IRRIGATION AND NITROGEN MANAGEMENT: THREE MAJOR PRACTICES IN CLOSING YIELD GAPS FOR AGRICULTURAL SUSTAINABILITY IN NORTH-WEST CHINA

Xiuwei GUO, Manoj Kumar SHUKLA, Di WU, Shichao CHEN, Donghao LI, Taisheng DU

期刊论文

Improved numerical method for time domain dynamic structure-foundation interaction analysis based onscaled boundary finite element method

DU Jianguo, LIN Gao

期刊论文

Performance analysis for a two-way relaying power line networkwith analog network coding

Yu-wen QIAN,Meng TIAN,Xue JIANG,Hua-ju SONG,Feng SHU,Jun LI

期刊论文

Conformal analysis of fundamental frequency of vibration of elastic clamped plates

QI Hongyuan, ZHU Hengjun

期刊论文

压力梯度作用下相干结构的演化

陆利蓬,李兆瑞

期刊论文

Anlotinib as third- or further-line therapy for short-term relapsed small-cell lung cancer: subgroupanalysis of a randomized phase 2 study (ALTER1202)

期刊论文

Development and case study of a new-generationmodel-VAT for analyzing the boundary conditions influence

Wenwei Yang, Yun Zhu, Carey Jang, Shicheng Long, Che-Jen Lin, Bin Yu, Zachariah Adelman, Shuxiao Wang, Jia Xing, Long Wang, Jiabin Li

期刊论文

Chemically reactive solute transfer in a boundary layer slip flow along a stretching cylinder

Swati Mukhopadhyay

期刊论文

Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

期刊论文

Evaluation of automated in-line precision dairy farming technology implementation in three dairy farms

Maria CARIA, Giuseppe TODDE, Antonio PAZZONA

期刊论文