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Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

《农业科学与工程前沿（英文）》 2018年第5卷第4期页码 455-461 doi: 10.15302/J-FASE-2018232

摘要：

Prewetting process can reduce the contact angle between the droplet and the leaf blade, so that the droplet can more easily wet and spread, thereby increasing the quantity of deposition. To improve the effectiveness of pesticides on cotton leaves, prewetting by single-rotor electric unmanned aerial vehicles (UAV) was studied, focusing on the effects of pesticide deposition on cotton leaves during the flowering period. Cotton leaves in 0°–30°, 30°–60°, 60°–90° leaf blade angle ranges (angle between the leaf blade and the horizontal plane) were examined. In the first experiment, four different prewetting volumes (0, 1.6, 3.2 and 4.8 L) were sprayed by a single-rotor electric UAV on four cotton plots (plots A to D) each with an area of 120 m , and then each area was sprayed with a 0.8% (w/v) ponceau 2R solution by another single-rotor electric UAV. The results revealed that with no prewetting, droplet deposition quantity decreased with increasing leaf blade inclination. After prewetting, the mean droplet deposition quantity on plots B, C and D increased by 39.8%, 9.7% and 24.9%, respectively. The prewetting rate of 1.6 L per 120 m had the most significant effect on improving the deposition of droplets. It was also found that the mean droplet deposition quantity in each leaf blade angle range increased after prewetting. For the leaf blade angle range 60° to 90°, this increase was the most pronounced, with 0.043, 0.062, 0.057 and 0.048 L·cm in plots A–D, respectively. Also, droplet deposition uniformity in the leaf blade angle range 60°–90° was better after prewetting. These results should provide a valuable reference for future research and practice to improve the effectiveness of pesticides applied to cotton by aerial applications.

关键词： aerial spray cotton deposition flowering period leaf angle prewetting UAV

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FLOWERING PLANTS AND ENTOMOPHAGOUS ARTHROPODS IN THE AGRICULTURAL LANDSCAPE: A PRACTISE-ORIENTED SUMMARY

《农业科学与工程前沿（英文）》 2022年第9卷第1期页码 63-74 doi: 10.15302/J-FASE-2021427

摘要：

There is a growing demand for high-quality agricultural products and more countries have adopted landscape management by sowing flowering plants in agricultural fields as an important branch of conservation biological control. However, there has been less concern over the interactions and trade-offs between floral plants and entomophagous arthropods. This paper review progress in pollen/nectar feeding habits of entomophagous insects including parasitoids and predators which are important natural enemies of crop pests in agricultural fields. Factors that influence the preference of different guilds of natural enemies are reviewed to guide the selection of flowering plants in conservation biological control practices. Most studies find that floral resources have positive effects on both biological traits of natural enemies and their abundance and diversity, and this is believed to contribute greatly to pest control. Furthermore, the potential impacts of floral resources on crop yields are also discussed with an emphasis on a guild of entomophagous insects that provides both pest control and pollination services.

关键词： ecosystem services / flowering plants / natural enemies / nectar / pollen

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Using hydrochemical signatures to characterize the long-period evolution of groundwater information in

《环境科学与工程前沿（英文）》 2021年第15卷第5期 doi: 10.1007/s11783-021-1393-7

摘要：

• The long-period groundwater evolution was identified by hydrochemical signatures.

关键词： Groundwater quality Hydrochemical signatures Spatial-temporal variations Water-rock interactions Anthropogenic interventions

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Mechanism design of reverse auction on concession period and generalized quality for PPP projects

Xianjia WANG, Shiwei WU

《工程管理前沿（英文）》 2017年第4卷第2期页码 156-170 doi: 10.15302/J-FEM-2017016

摘要： Reverse auctions of PPP projects usually require the bid to specify several characteristics of quality and the concession period to be fulfilled. This paper sets up a summary function of generalized quality, which contributes to reducing the dimensions of information. Thus, the multidimensional reverse auction model of a PPP project can be replaced by a two-dimensional direct mechanism based on the concession period and the generalized quality. Based on the theory of the revelation principle, the feasibility conditions, equilibrium solution and generalized quality requirements of such a mechanism, considering the influence of a variable investment structure are described. Moreover, two feasible multidimensional reverse auctions for implementing such a direct mechanism: Adjusting the scoring function and establishing a special reverse auction rule are built. The analysis shows that in these types of reverse auctions, optimal allocation can be achieved, the social benefit under the incomplete information will be maximized, and the private sector with the highest integrated management level wins the bid. In such a direct mechanism, the investment and financial pressure of the public sector can be reduced.

关键词： PPP project reverse auction mechanism design multidimensional information scoring function two-stage bidding

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A novel period estimation method for X-ray pulsars based on frequency subdivision

Li-rong SHEN,Xiao-ping LI,Hai-feng SUN,Hai-yan FANG,Meng-fan XUE

《信息与电子工程前沿（英文）》 2015年第16卷第10期页码 858-870 doi: 10.1631/FITEE.1500052

摘要： Period estimation of X-ray pulsars plays an important role in X-ray pulsar based navigation (XPNAV). The fast Lomb periodogram is suitable for period estimation of X-ray pulsars, but its performance in terms of frequency resolution is limited by data length and observation time. Longer observation time or oversampling can be employed to improve frequency analysis results, but with greatly increased computational complexity and large amounts of sampling data. This greatly restricts real-time autonomous navigation based on X-ray pulsars. To resolve this issue, a new method based on frequency subdivision and the continuous Lomb periodogram (CLP) is proposed to improve precision of period estimation using short-time observation data. In the proposed method, an initial frequency is first calculated using fast Lomb periodogram. Then frequency subdivision is performed near the initial frequency to obtain frequencies with higher precision. Finally, a refined period is achieved by calculating the CLP in the obtained frequencies. Real data experiments show that when observation time is shorter than 135 s, the proposed method improves period estimation precision by 1–3 orders of magnitude compared with the fast Lomb periodogram and fast Fourier transform (FFT) methods, with only a slight increase in computational complexity. Furthermore, the proposed method performs better than efsearch (a period estimation method of HEAsoft) with lower computational complexity. The proposed method is suitable for estimating periods of X-ray pulsars and obtaining the rotation period of variable stars and other celestial bodies.

关键词： Pulsar navigation Period estimation Frequency subdivision Continuous Lomb periodogram

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Experimental research on the multilayer compartmental particle damper and its application methods on long-period

Zhenyuan LUO, Weiming YAN, Weibing XU, Qinfei ZHENG, Baoshun WANG

《结构与土木工程前沿（英文）》 2019年第13卷第4期页码 751-766 doi: 10.1007/s11709-018-0509-z

摘要： Particle damping technology has attracted extensive research and engineering application interest in the field of vibration control due to its prominent advantages, including wide working frequency bands, ease of installation, longer durability and insensitivity to extreme temperatures. To introduce particle damping technology to long-period structure seismic control, a novel multilayer compartmental particle damper (MCPD) was proposed, and a 1/20 scale test model of a typical long-period self-anchored suspension bridge with a single tower was designed and fabricated. The model was subjected to a series of shaking table tests with and without the MCPD. The results showed that the seismic responses of the flexible or semi-flexible bridge towers of long-period bridges influence the seismic responses of the main beam. The MCPD can be conveniently installed on the main beam and bridge tower and can effectively reduce the longitudinal peak displacement and the root mean square acceleration of the main beam and tower. In addition, no particle accumulation was observed during the tests. A well-designed MCPD can achieve significant damping for long-period structures under seismic excitations of different intensities. These results indicate that the application of MCPDs for seismic control of single-tower self-anchored suspension bridges and other long-period structures is viable.

关键词： energy dissipation devices multilayer compartmental particle damper self-anchored suspension bridges shaking tables test long-period structure seismic control

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Russian school of the theory and geometry of gearing: Its origin and golden period (1935 --1975)

Dmitry BABICHEV,Sergey LAGUTIN,Natalya BARMINA

《机械工程前沿（英文）》 2016年第11卷第1期页码 44-59 doi: 10.1007/s11465-015-0360-z

摘要：

During the second half of the twentieth century, Soviet scientists were among the world leaders in the theory and geometry of gearing or the theoretical fundamentals of designing gears and gear-cutting tools. The authors of the current paper review works related to the development of the theory of gearing (TG) written in Russian from the mid-1930s to the present. Overall, the review covers more than 400 publications of nearly 200 authors (among more than 1000 studied works). This review involves some works on gear strength and accuracy to attract more experts.

This paper presents a short list of works from the seventeenth century to the nineteenth century and discusses the basic concepts of the TG. This paper also includes a review of more than 160 papers in Russian for the period of 1935–1975, which is the “golden age” of the TG. The main features and achievements during this period are also considered.

The distinctive feature of this review is the use of diagrams that visually present TG experts and the dates and themes of their published works. The diagrams also show the following aspects: 1) The most popular and important themes in a specific period, 2) the most important publications on the themes of interest to readers, and 3) the direction of the works and scope of interests of every researcher.

关键词： theory of gearing (TG) gear geometry generating surface gear synthesis gear analysis

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埋地热油管道运行参数的准周期变化

崔慧

《中国工程科学》 2006年第8卷第1期页码 51-53

摘要：

从理论上分析了在大气温度变化的影响下埋地热油管道的运行参数以及周围土壤环境均随季节变化而呈现准周期变化规律，在分析大量实际运行数据的基础上，进一步验证了该规律的合理性，建议在有关管道的节能降耗、优化运行以及经济清蜡等问题的研究中，应该考虑运行参数的滞后影响。

关键词：热油管道大气温度土壤环境准周期

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Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation period

Nanqi REN, Han KANG, Xiuheng WANG, Nan LI

《环境科学与工程前沿（英文）》 2011年第5卷第2期页码 277-282 doi: 10.1007/s11783-010-0226-x

摘要： Sequencing batch reactor (SBR) for enhanced biological phosphorus removal (EBPR) processes was used to investigate the impact of the temperature shock on the competition between phosphorus-accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) in start-up stage. During the 34 days operation, SBR was set with temperature variation(0–5 d, 22±1°C; 6–13 d, 29±1°C; 14–34 d, 14±1°C). PAOs and GAOs were analyzed by fluorescent in situ hybridization (FISH), and intracellular polyphosphate granules were stained by Neisser-stain. The results showed that the influence of temperature shock on PAOs’ abundance was more serious than that on GAOs in the enriching process. Under sudden and substantially temperature variation, from 22±1°C to 29±1°C and then to 14±1°C, the domination of PAOs was deteriorated. After temperature shock, PAOs’ competitive advantages at low temperature that concluded in other study did not appear in our study. As mesophilic, GAOs (indicated by and ) were more temperature adaptive and better grew and took the domination at 14±1°C in the end. In the competition process, organisms of tetrad forming organisms (TFOs)-like shape which were considered as typical GAOs, were observed. With the evidence of poly-P granules containing by Neisser-straining and result of FISH, these organisms of TFOs-like shape were better to be assumed as adaption state or a special self-protecting shape of PAOs.

关键词： fluorescent in situ hybridization (FISH) tetrad forming organisms (TFOs) temperature variation enhanced biological phosphorus removal (EBPR)

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analysis in conventional and organic rice production systems and organic scenarios in the transition period

Hamed MANSOORI, Parviz Rezvani MOGHADDAM, Rooholla MORADI

《能源前沿（英文）》 2012年第6卷第4期页码 341-350 doi: 10.1007/s11708-012-0206-x

摘要： Compared to conventional agriculture, organic agriculture is reported to be more efficient and effective in reducing water and soil pollution, greenhouse gases (GHGs) emission and risk of human health. In additional, field management under organic condition can be useful for increasing energy efficiency. Rice is one of the important crops which are cultivated in two forms, organic and conventional, in Iran. In order to compare the energy efficiency and economic analysis of rice production in organic and conventional systems in Iran, needed information was collected by face-to-face questionnaire in 2011 and three scenarios were designed to predict the changes of energy budget and economic analysis in the transition period that included: 25%, 50% and 75% organic management in rice production. The results showed that all energy indexes were improved in organic rice production compared to conventional condition. Higher values of benefit to cost ratio, gross and net return and lower value of total cost of production were obtained from organic rice production which indicated that the organic management of farm improved economically in comparison with the conventional rice production system. The shares of direct and renewable energies were increased by approach to organic management. Increase in energy efficiency and productivity was predicted for the transition period but decrease trend in economic indexes was projected for this period in all scenarios. The main reason for decreasing economic indexes in organic scenarios was that the market price of organic rice was the same as that of conventional rice in the transition period.

关键词： energy efficiency specific energy net return Cobb-Douglas function

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渤海湾海底隧道运营风险评估分析

王永红,刘兵,张永刚

《中国工程科学》 2013年第15卷第12期页码 107-112

摘要：

特长海底隧道运营是一个极其复杂的系统工程，存在较大的不确定性和安全风险。根据隧道工程运营期风险评估的一般流程，对渤海湾海底隧道工程在其运营期的风险进行了评估。评估中考虑的主要风险因素有水害、衬砌裂损、冻害、衬砌腐蚀、震害、洞内空气污染、火灾和列车脱轨事故8 种类型。综合运用信心指数法和层次分析法，参照隧道与地下工程风险接受准则和风险等级标准，对渤海湾海底隧道运营期间的风险进行估计与评价。给出了该海底隧道运营期的风险等级，并讨论了本评估工作中尚存在的一些问题和今后有待深入的工作。

关键词：海底隧道运营期风险分析风险评估

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苏通大桥短期观测流速在设计基准期内的应用

苏慧,龚维明,梁书亭

《中国工程科学》 2006年第8卷第7期页码 42-46

摘要：

对缺乏长期流速资料的地区，给出了一种通过当地短期流速资料推算设计基准期参考流速的方法；通过分析苏通长江公路大桥水流速度观测的有关内容，采用实测的短期实际流速记录建立流速概率分布模型，按小样本推算极值的办法，得到大桥的设计基准期的基本流速并进行相关分析，确认计算结果的合理性，建立线性回归方程；为确保大桥在动力荷载作用下的安全应用及苏通大桥工程设计、施工提供可靠的技术指导。

关键词：短期观测设计基准期流速相关分析回归方程

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基于抗浮稳定的盾构隧道合理覆土厚度研究

刘学彦,袁大军,姜曦

《中国工程科学》 2015年第17卷第1期页码 88-95

摘要：

运用理论分析和数值计算相结合的方法，分别从施工期和运营期角度提出了隧道抗浮稳定合理覆土厚度设定原则和理论计算方法；对于隧道施工期，考虑土体侧向摩阻力和管片环间摩阻力的影响等较为有利因素，同时考虑未凝浆液的影响等不利因素，建立了合理覆土厚度的理论计算公式；对于隧道运营期，建议只考虑隧道上覆土体自重进行抗浮，对于存在洪水冲刷的隧道设计，其上覆土体厚度还要加上设计冲刷深度；为南京某在建隧道的纵断面设计提供了一定的参考，同时也为其他过江海盾构隧道满足抗浮稳定的覆土厚度设定提供理论支持。

关键词：抗浮安全；隧道施工期；隧道运营期；覆土厚度

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基于表面肌电信号的行走环境与步态周期识别 Special Feature on Intelligent Robats

Seulki KYEONG, Wonseok SHIN, Minjin YANG, Ung HEO, Ji-rou FENG, Jung KIM

《信息与电子工程前沿（英文）》 2019年第20卷第3期页码 342-352 doi: 10.1631/FITEE.1800601

摘要：在外骨骼机器人控制研究中，识别及预测操作者运动意图是一项很大挑战。外骨骼机器人是一种检测和驱动人体运动的机械动力装置，因其复杂的人机交互技术，需要使用很多不同类型传感器。当使用各种传感器时，需要选择数据类型以进行有效传感。肌电信号能在实际运动做出之前识别预期动作，并且可以缩短外骨骼机器人控制中的时间延迟。为应用下肢外骨骼帮助行走，本文工作旨在使用不同类型传感器（包括表面肌电信号传感器）识别行走环境和区分步态周期。为此，将地面反作用力、人机相互作用力、位置传感器和表面肌电信号传感器相结合，对4个受试者进行步态实验。本文展示了在行走环境与步态周期的识别中使用表面肌电信号及其他类型传感器的实验成果。选择不同传感器类型组合、表面肌电信号传感器不同位置组合以及表面肌电信号不同特征值组合，作为有效数据类型。实验结果表明，与使用单个力学传感器相比，将表面肌电信号传感器与其结合使用，可使识别结果得到很大改善。此外，在3种不同类型传感器的不同组合中，使用表面肌电信号与位置传感器信息的组合得出最高分类准确率。当使用全部4种类型传感器时，行走环境与步态周期分类准确率分别为96.1%与97.8%。在腿部5个表面肌电传感器不同位置组合里，股内侧肌和腓肠肌组合是最有效的2种肌肉类型组合。当仅使用表面肌电信号进行分类时，该组合在行走环境识别实验中，足跟接地前与足趾离地前的情况下，分类准确率分别为74.4%与71.7%；步态周期分类准确率为68%。两组有效的表面肌电信号特征值组合分别是“平均绝对值、过零点数”与“平均绝对值、波形长度”。“平均绝对值、过零点书”特征组合在行走环境识别实验中，在足跟接地前与足趾离地前情况下，分类准确率分别为80%与77.1%；步态周期分类准确率为75.5%。上述结果表明，表面肌电信号可有效用于控制外骨骼机器人。

关键词：行走环境；步态周期；表面肌电信号；外骨骼

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全球供应链中残次品返工与多期延迟付款和部分延迟订购整合的协同效应 Article

Waqas Ahmed, Muhammad Moazzam, Biswajit Sarkar, Saif Ur Rehman

《工程（英文）》 2021年第7卷第2期页码 260-271 doi: 10.1016/j.eng.2020.07.022

摘要：

在洲际贸易和经济中，商品是从全球供应商那里购买的。有时，预期批次可能包括一小部分残次品。这些残次品可以在修理后出售给顾客，因而仍具有价值。在附近的维修车间对此类产品进行返工而不是退货，既经济划算又可持续。当缺货数量与残次品数量一致时，返工产品可以从车间返回给买方。同时，供应商也会相应地与采购商采取多期延迟付款的策略。整体利润通过中期融资的回报得到最大程度的提高。本研究的目的是建立一个协同库存模型，通过考虑返工、多期延迟付款政策及库存短缺等因素，以获得最大的利润。该模型的研究结果表明，在库存乐观的情况下，通过监控周期时间和阶段比例，可以提高供应链的库存管理绩效。结果证明，当供应商给予买方的许可期限等于或大于生产周期时，利润较小；反之，则利润较大。本文采用代数方法求解封闭系统的最优解。本研究的数学实验旨在提供管理见解与切实可行的实践。

关键词：残次品返工短缺多期延迟付款非衍生方法