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Reducing CO emissions from the rebalancing operation of the bike-sharing system in Beijing

《工程管理前沿（英文）》 2023年第10卷第2期页码 262-284 doi: 10.1007/s42524-021-0168-y

摘要： With the development of the bike-sharing system (BSS) and the introduction of green and low carbon development, the environmental impacts of BSS had received increasing attention in recent years. However, the emissions from the rebalancing of BSS, where fossil-fueled vehicles are commonly used, are usually neglected, which goes against the idea of green travel in a sharing economy. Previous studies on the bike-sharing rebalancing problem (BRP), which is considered NP-hard, have mainly focused on algorithm innovation instead of improving the solution model, thereby hindering the application of many existing models in large-scale BRP. This study then proposes a method for optimizing the CO₂ emissions from BRP and takes the BSS of Beijing as a demonstration. We initially analyze the spatial and temporal characteristics of BSS, especially the flow between districts, and find that each district can be independently rebalanced. Afterward, we develop a rebalancing optimization model based on a partitioning strategy to avoid deciding the number of bikes being loaded or unloaded at each parking node. We then employ the tabu search algorithm to solve the model. Results show that (i) due to over launch and lack of planning in rebalancing, the BSS in Beijing shows great potential for optimization, such as by reducing the number of vehicle routes, CO₂ emissions, and unmet demands; (ii) the CO₂ emissions of BSS in Beijing can be reduced by 57.5% by forming balanced parking nodes at the end of the day and decreasing the repetition of vehicle routes and the loads of vehicles; and (iii) the launch amounts of bikes in specific districts, such as Shijingshan and Mentougou, should be increased.

关键词： bike-sharing CO₂ emissions environmental benefit partitioning strategy rebalancing problem

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Optimization of thread partitioning parameters in speculative multithreading based on artificial immune

Yu-xiang LI,Yin-liang ZHAO,Bin LIU,Shuo JI

《信息与电子工程前沿（英文）》 2015年第16卷第3期页码 205-216 doi: 10.1631/FITEE.1400172

摘要： Thread partition plays an important role in speculative multithreading (SpMT) for automatic parallelization of irregular programs. Using unified values of partition parameters to partition different applications leads to the fact that every application cannot own its optimal partition scheme. In this paper, five parameters affecting thread partition are extracted from heuristic rules. They are the dependence threshold (DT), lower limit of thread size (TSL), upper limit of thread size (TSU), lower limit of spawning distance (SDL), and upper limit of spawning distance (SDU). Their ranges are determined in accordance with heuristic rules, and their step-sizes are set empirically. Under the condition of setting speedup as an objective function, all combinations of five threshold values form the solution space, and our aim is to search for the best combination to obtain the best thread granularity, thread dependence, and spawning distance, so that every application has its best partition scheme. The issue can be attributed to a single objective optimization problem. We use the artificial immune algorithm (AIA) to search for the optimal solution. On Prophet, which is a generic SpMT processor to evaluate the performance of multithreaded programs, Olden benchmarks are used to implement the process. Experiments show that we can obtain the optimal parameter values for every benchmark, and Olden benchmarks partitioned with the optimized parameter values deliver a performance improvement of 3.00% on a 4-core platform compared with a machine learning based approach, and 8.92% compared with a heuristics-based approach.

关键词： Speculative multithreading Thread partitioning Artificial immune algorithm

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Partitioning of heavy metals during municipal solid waste incineration on a laboratory fluid bed furnace

LI Jianxin, YAN Jianhua, CHI Yong

《能源前沿（英文）》 2007年第1卷第3期页码 359-364 doi: 10.1007/s11708-007-0054-2

摘要： The content of heavy metals in the main physical compositions of municipal solid waste (MSW) is analyzed. The effects of temperature, chlorine and water on the partitioning of heavy metals are studied using a laboratory fluidized-bed (FB) furnace with simulated MSW composition. The experimental results show that temperature and chloride content in the feed have significant influence on the volatility of heavy metals, especially those of lower boiling point such as Hg, Cd and Zn. The influence of water is slight.

关键词： partitioning municipal volatility significant influence temperature

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Particulate matter and metals partitioning in highway rainfall-runoff

Gaoxiang YING, John J. SANSALONE,

《环境科学与工程前沿（英文）》 2010年第4卷第1期页码 35-46 doi: 10.1007/s11783-010-0009-4

摘要： This study investigated the particulate matter (PM) and metals in highway dry deposition and rainfall-runoff as a function of hydrologic transport and settling on an event basis. Events were differentiated as mass-limited (ML) and flow-limited (FL). Results indicate that unique and separate suspended sediment concentration (SSC) relationships with turbidity occurred for ML and FL events. Sixty minutes of quiescent settling produced a single SSC-turbidity relationship for all events. ML events transport higher proportions of settleable and sediment PM while FL events transported relatively higher suspended PM. For batch clarification with one hour of settling, ML events had generally higher treatment efficiencies compared to FL events for the same settling conditions. Highway dry deposition PM was hetero-disperse and coarse ( = 304 µm). Results indicate that the acidic rainfall is not a significant contributor to metals in runoff but is capable of leaching metals from dry deposition PM into runoff. Partitioning in retained runoff resulted in a particulate-bound €predominance €for €most €metals €except Ca and Mg. While the finer fraction of dry deposition PM (<75µm) generates the highest metal concentrations, the highest metal mass is associated with the coarser fraction (>75µm).

关键词： stormwater particulate matter (PM) turbidity suspended sediment concentration (SSC) unit operations metals dry deposition acid rain

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Comparison of evapotranspiration and energy partitioning related to main biotic and abiotic controllers

Lei GAO, Peng ZHAO, Shaozhong KANG, Sien LI, Ling TONG, Risheng DING, Hongna LU

《农业科学与工程前沿（英文）》 2020年第7卷第4期页码 490-504 doi: 10.15302/J-FASE-2019310

摘要：

Knowledge of evapotranspiration (ET) and energy partitioning is useful for optimizing water management, especially in areas where water is scarce. A study was undertaken in a furrow-irrigated vineyard (2015) and a drip-irrigated vineyard (2017) in an arid region of north-west China to compare vineyard ET and energy partitioning and their responses to soil water content (SWC) and leaf area index (LAI). ET and soil evaporation (E) and transpiration (T) were determined using eddy covariance, microlysimeters, and sap flow. Seasonal average E/ET, T/ET, crop coefficient (Kc), evaporation coefficient (Ke), and basal crop coefficient (Kcb) were 0.50, 0.50, 0.67, 0.35, and 0.29, respectively, in the furrow-irrigated vineyard and 0.42, 0.58, 0.57, 0.29, and 0.43 in the drip-irrigated vineyard. The seasonal average partitioning of net radiation (Rn) into the latent heat flux (LE), sensible heat flux (H) and soil heat flux (G) (LE/Rn, H/Rn, and G/Rn), evaporative fraction (EF) and Bowen ratio (β) were 0.57, 0.26, 0.17, 0.69 and 0.63, respectively, in the furrow-irrigated vineyard and 0.46, 0.36, 0.17, 0.57 and 0.97 in the drip-irrigated vineyard. The LE/Rn, H/Rn, EF, and β were linearly correlated with LAI. The E, Kc, Ke, E/ET, LE/Rn, LEs/Rn (ratio of LE by soil E to Rn), H/Rn, EF and β were closely correlated with topsoil SWC (10 cm depth). Responses of ET and energy partitioning to the LAI and SWC differed under the two irrigation methods. Drip irrigation reduced seasonal average E/ET and increased average T/ET. From the perspective of energy partitioning, seasonal average H/Rn increased whereas LE/Rn, especially LEs/Rn, decreased. Compared with furrow irrigation, drip irrigation decreased the proportion of unproductive water consumption thereby contributing to enhanced water use efficiency and accumulation of dry matter.

关键词： crop coefficient eddy covariance microlysimeter sap flow soil evaporation transpiration

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两相分配生物反应器——浊点系统在生物转化中的应用

王志龙

《中国工程科学》 2005年第7卷第5期页码 73-78

摘要：

利用两相分配生物反应器可以控制底物由非水相向水相释放，增加底物的溶解度和解除底物对微生物的抑制，保护产物降解，降低下游分离费用；论述了两相分配生物反应器的基本原理和发展概况，并以胆固醇边链切除生物转化为例，介绍了新开发的浊点系统两相分配生物反应器的巨大潜力。

关键词：两相分配生物转化非离子表面活性剂浊点系统生物反应器

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干旱和复水对冬小麦光合产物分配格局的影响

谷艳芳,丁圣彦,高志英,邢倩

《中国工程科学》 2012年第14卷第3期页码 59-64

摘要：

于2005—2006年在中国科学院封丘农田生态实验站研究了不同水分处理下冬小麦光合产物分配格局及其动态。实验设全生育期干旱处理和充分供水处理以及干旱后拔节期、孕穗期、开花期复水处理。结果显示：不同生育期复水对冬小麦由于干旱胁迫引起的生物量下降有补偿作用；干旱和复水能改变器官水平上光合产物的分配格局；干旱胁迫引起叶、穗分配降低，并使茎、叶鞘和根分配指数上升；拔节期复水使叶光合产物分配指数增加、茎分配指数下降；孕穗期和开花期复水能提高光合产物在茎和穗中的分配；不同时期复水对干旱胁迫引起的产量下降均有不同程度的补偿作用，拔节期复水主要提高小麦单株穗数、孕穗期和开花期复水以提高千粒重为主。

关键词：光合产物分配指数可溶性糖冬小麦干旱和复水

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Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential evolution algorithm

《能源前沿（英文）》页码 782-795 doi: 10.1007/s11708-023-0905-8

摘要： China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.

关键词： distributed photovoltaics (DPVs) cluster partitioning improved differential evolution algorithm voltage control consumption capacity of distributed photovoltaics

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基于自适应四叉树分块与最高有效位预测的大容量密文域可逆信息隐藏算法 Research Article

祁凯莉,张敏情,狄富强,孔咏骏

《信息与电子工程前沿（英文）》 2023年第24卷第8期页码 1156-1168 doi: 10.1631/FITEE.2200501

摘要：为提高密文域可逆信息隐藏（reversible data hiding in encrypted images，RDH-EI）算法的嵌入容量，提出一种基于自适应四叉树分块和最高有效位（most significant bit，MSB）预测的大容量RDH-EI方案。首先根据图像的平滑程度进行自适应四叉树分块，然后将不同大小的块进行块级加密和置乱，以抵抗对于加密图像的分析。在嵌入数据阶段，对于文献Wang & He（2022）提出的自适应MSB预测方法进行改进，以块中左上角像素为目标像素，用于预测其它像素，从而腾出更多嵌入空间。首次将四叉树分块方法应用于密文域图像的可逆信息隐藏。模拟结果表明，所提方法具有可逆性与可分离性，并且在自适应MSB预测方法基础上进一步提高了平均嵌入容量。对于512×512大小的灰度图像，平均嵌入容量提高约25 565比特，对于所有嵌入容量有所提高的较平滑图像，平均嵌入容量提高约35 530比特。

关键词：自适应四叉树分块；自适应最高有效位预测；密文域可逆信息隐藏；高嵌入容量

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高性能节约型不锈钢制备技术研发与应用

谢胜涛,刘振宇,王国栋

《中国工程科学》 2014年第16卷第1期页码 81-87

摘要：

开发了409L和410S铁素体不锈钢冷轧板的淬火-配分（Q&P）工艺，获得了铁素体、马氏体和残余奥氏体的复相组织。通过优化奥氏化温度、淬火温度和配分时间，获得了尽量多的马氏体和残余奥氏体。与常规退火和淬火-回火（Q&T）工艺相比，Q&P工艺获得了最优的强度和延伸率组合、连续性屈服和适中的n值、r值，达到了高强度和易成型的要求，能够替代先进高强钢用于生产汽车结构件。

关键词：不锈钢淬火配分高强度易成型

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Effects of irrigation and nitrogen management on hybrid maize seed production in north-west China

Hui RAN,Shaozhong KANG,Fusheng LI,Ling TONG,Taisheng DU

《农业科学与工程前沿（英文）》 2016年第3卷第1期页码 55-64 doi: 10.15302/J-FASE-2016091

摘要： Scientific irrigation and nitrogen management is important for agricultural production in arid areas. To quantify the effect of water and nitrogen management on yield components, biomass partitioning and harvest index ( ) of maize for seed production with plastic film-mulching, field experiments including different irrigation and N treatments were conducted in arid north-west China in 2013 and 2014. The results indicated that kernel number per plant ( ) was significantly affected by irrigation and N treatments. However, 100-kernel weight was relatively stable. Reducing irrigation quantity significantly increased stem partitioning index ( ) and leaf partitioning index ( ), and decreased ear partitioning index ( ) at harvest, but lowering N rate (from 500 to 100 kg N·hm ) did not significantly reduce , , and at harvest. was significantly reduced by reducing irrigation quantity, but not by reducing N rate. Linear relationships were found between , , , at harvest and and evapotranspiration ( ).

关键词： yield components biomass partitioning harvest index irrigation nitrogen maize for seed production

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Determination of polyfluoroalkyl compounds in water and suspended particulate matter in the river Elbe and North Sea, Germany

Lutz AHRENS, Merle PLASSMANN, Zhiyong XIE, Ralf EBINGHAUS

《环境科学与工程前沿（英文）》 2009年第3卷第2期页码 152-170 doi: 10.1007/s11783-009-0021-8

摘要： The distribution of polyfluoroalkyl compounds (PFCs) in the dissolved and particulate phase and their discharge from the river Elbe into the North Sea were studied. The PFCs quantified included C -C perfluorinated sulfonates (PFSAs), 6∶2 fluorotelomer sulfonate (6∶2 FTS), C and C perfluorinated sulfinates (PFSiAs), C -C perfluorinated carboxylic acids (PFCAs), perfluoro-3,7-dimethyl-octanoic acid (3,7m -PFOA), perfluorooctane sulfonamide (FOSA), and n-ethyl perfluroctane sulfonamidoethanol (EtFOSE). PFCs were mostly distributed in the dissolved phase, where perfluorooctanoic acid (PFOA) dominated with 2.9-12.5 ng/L. In the suspended particulate matter FOSA and perfluorooctane sulfonate (PFOS) showed the highest concentrations (4.0 ng/L and 2.3 ng/L, respectively). The total flux of ∑PFCs from the river Elbe was estimated to be 802 kg/year for the dissolved phase and 152 kg/year for the particulate phase. This indicates that the river Elbe acts as a source of PFCs into the North Sea. However, the concentrations of perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) in the North Sea were higher than that in the river Elbe, thus an alternative source must exist for these compounds.

关键词： polyfluoroalkyl compounds (PFCs) perfluorooctane sulfonate (PFOS) perfluorooctanoic acid (PFOA) surface water water-particulate partitioning

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Kd-tree and quad-tree decompositions for declustering of 2D range queries over uncertain space

Ahmet SAYAR,Süleyman EKEN,Okan ÖZTÜRK

《信息与电子工程前沿（英文）》 2015年第16卷第2期页码 98-108 doi: 10.1631/FITEE.1400165

摘要： We present a study to show the possibility of using two well-known space partitioning and indexing techniques, kd trees and quad trees, in declustering applications to increase input/output (I/O) parallelization and reduce spatial data processing times. This parallelization enables time-consuming computational geometry algorithms to be applied efficiently to big spatial data rendering and querying. The key challenge is how to balance the spatial processing load across a large number of worker nodes, given significant performance heterogeneity in nodes and processing skews in the workload.

关键词： Kd tree Quad tree Space partitioning Spatial indexing Range queries Query optimization

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基于质量感知的水下图像自适应压缩方法 Regular Papers

Ya-qiong CAI, Hai-xia ZOU, Fei YUAN

《信息与电子工程前沿（英文）》 2019年第20卷第5期页码 716-730 doi: 10.1631/FITEE.1700737

摘要：水下图像压缩是水声图像传输系统中必不可少并且至关重要的一个环节，有效的预测感知压缩图像的质量能使系统在压缩过程更好的调整压缩率，提高图像传输通信系统的效率。本文首先分别对压缩感知和嵌入式编码两种压缩策略下的水下压缩图像进行质量感知，然后利用图像活动性IAM（Image Activity Measurement）与BPP-SSIM（Bits Per Pixel and Structural SIMilarity）曲线间的映射进行建模并获得模型参数，从而根据图像的空域活动性、压缩率和压缩策略预测图像的压缩质量。实验结果表明本文所建立的模型能有效拟合水下图像的压缩质量曲线，根据模型中参数所具有的规律性能在小误差范围内预测出水下压缩图像的感知质量。本文所提出的方法能够有效的预测感知水下图像的压缩质量，并有效权衡压缩率与压缩质量之间的关系，减小发送端的数据缓存压力，提高水下图像通信系统的效率。

关键词：水下图像压缩；SPIHT压缩；压缩感知；压缩质量预测

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Equipment–process–strategy integration for sustainable machining: a review

《机械工程前沿（英文）》 2023年第18卷第3期 doi: 10.1007/s11465-023-0752-4

摘要： Although the manufacturing industry has improved the quality of processing, optimization and upgrading must be performed to meet the requirements of global sustainable development. Sustainable production is considered to be a favorable strategy for achieving machining upgrades characterized by high quality, high efficiency, energy savings, and emission reduction. Sustainable production has aroused widespread interest, but only a few scholars have studied the sustainability of machining from multiple dimensions. The sustainability of machining must be investigated multidimensionally and accurately. Thus, this study explores the sustainability of machining from the aspects of equipment, process, and strategy. In particular, the equipment, process, and strategy of sustainable machining are systematically analyzed and integrated into a research framework. Then, this study analyzes sustainable machining-oriented machining equipment from the aspects of machine tools, cutting tools, and materials such as cutting fluid. Machining processes are explored as important links of sustainable machining from the aspects of dry cutting, microlubrication, microcutting, low-temperature cutting, and multidirectional cutting. The strategies for sustainable machining are also analyzed from the aspects of energy-saving control, machining simulation, and process optimization of machine tools. Finally, opportunities and challenges, including policies and regulations toward sustainable machining, are discussed. This study is expected to offer prospects for sustainable machining development and strategies for implementing sustainable machining.

关键词： sustainable machining equipment process strategy manufacturing