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动力学 2

多输入多输出 2

360°表征 1

3S 1

BP神经网络 1

BRT专用道 1

CDMA 1

CP）；符号间干扰（inter symbol interference， ISI）；载波间干扰（inter carrier interference 1

GA-BP网络 1

GPS 1

HeNe激光器 1

ICI）；最大似然估计（maximum likelihood estimation 1

ISO 18186 1

IgG抗体 1

KTP 1

LM331型电压-频率转换器 1

MLE） 1

Maradbcm算法 1

OFDM）；快速傅立叶变换（Fast Fourier transform， FFT）；循环前缀（cyclic prefix 1

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一种通过循环前缀再利用改善OFDM系统带宽的新型节能ICI消除技术 Article

Sandeep SAROWA, Harmanjeet SINGH, Sunil AGRAWAL, B. S. SOHI

《信息与电子工程前沿（英文）》 2017年第18卷第11期页码 1892-1899 doi: 10.1631/FITEE.1601333

摘要：作为一项非常有前景的技术，正交频分复用（orthogonal frequency division multiplexing, OFDM）解决了频谱分配中的带宽不足问题，引领了无线移动通信领域的发展。

关键词：正交频分复用（orthogonal frequency division multiplexing OFDM）；快速傅立叶变换（Fast Fourier transform， FFT）；循环前缀（cyclic

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分层空时码多载波CDMA的译码与检测

杨洁,酆广增

《中国工程科学》 2007年第9卷第1期页码 58-62

摘要：

研究V－BLAST MIMO MC－CDMA下行系统。提出了一种对每个子载波进行V－BLAST译码的非线性算法，对不同天线数、用户数情况进行了系统的仿真和分析，并对V－BLAST译码的线性和非线性算法进行了系统仿真比较。

关键词：多输入多输出正交频分复用分层空时码迫零算法最小均方误差

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OFDM直接变频接收机中通用的I/Q不平衡估计与补偿方法 None

Fang-lin GU, Shan WANG, Wen-wu WANG

《信息与电子工程前沿（英文）》 2018年第19卷第3期页码 388-397 doi: 10.1631/FITEE.1700003

摘要：直接变频接收机由于具有低功耗的特点，受到广泛关注，但是它存在较严重的同相/正交（I/Q）分量不平衡问题：I/Q不平衡会恶化接收信号的信噪比，进而影响系统的传输容量和能够支持的调制方式。本文首先分析了I/Q不平衡对OFDM接收机接收信号的影响，在此基础上，定义了一个统计量用于刻画OFDM系统的I/Q不平衡特性，并提出一种实现I/Q不平衡参数估计与补偿的方法。特别地，进一步证明该统计量不受传输信道影响，因而该方法适用于高斯白噪声和多径衰落信道等不同场景。仿真结果表明，该方法可以实现对OFDM系统I/Q不平衡的准确估计与补偿，使补偿后系统的误比特率性能接近于不存在I/Q不平衡的情形。更重要的是，由于该方法不依赖于导频信号，因而可以应用于采用不同标准的OFDM系统。

关键词：同相/正交分量不平衡；正交频分复用；标准独立

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基于非完美信道状态的下行OFDMA系统中优化物理层安全问题的资源分配算法研究 None

Wei YANG, Jing MAO, Chen CHEN, Xiang CHENG, Liu-qing YANG, Hai-ge XIANG

《信息与电子工程前沿（英文）》 2018年第19卷第3期页码 398-408 doi: 10.1631/FITEE.1700026

摘要：介绍了一种基于正交频分多址（OFDMA）技术的下行通信系统中优化物理层安全问题的资源分配方案。假设系统中存在多名合法用户和一名采取“被动窃听”方式的非法入侵者，同时考虑基站端收到合法用户和窃听者的信道状态信息均含有误差。讨论了3种非完美信道状态信息情况，分别是：（1）信道信息存在估计误差；（2）信道信息反馈存在时延，需要通过预测估计当前信道状态；（3）反馈信道容量受限，导致量化误差，运用率失真理论可以推导出反馈信道容量的下界。我们把优化问题建模成一个功率和子载波的联合分配问题，优化目标为最大化用户最小的遍历安全容量。该优化问题是一个混合整数非线性规划问题，最优解计算复杂度较高。为降低求解复杂度，提出一种两步次优算法，分别进行子载波分配和功率分配。在给定某种子载波分配方案时，可以通过一种多项式复杂度算法，得出最优功率分配方案。仿真结果证明我们提出的算法在性能上可以逼近最优解。

关键词：资源分配；正交频分多址（OFDMA）；非完美信道状态信息；物理层安全

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波长三次重用的多波长星形光网络及其性能分析

甘朝钦

《中国工程科学》 2002年第4卷第10期页码 84-89

摘要：

通过引入分布式结构+反馈回路+波长分组的方法，提出了一种新的波长三次重用的多波长星形光网络。这种新的网络通过多耦合器内连和网络所有信道波长的三次重用，使网络规模和网络最大吞吐量都达到常规WDM星形网的4倍；通过单纤双向传输，在网络节点数相同的条件下，可节省光纤50%；通过采用分布式结构，使网络的抗毁性得到大幅度提高。

关键词：波分复用波长重用可调多波长选择路由器分布式结构反馈回路波长分组

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车路集成环境下BRT专用道时分复用的车路协作方法研究

董红召,凌越,刘冬旭,郭明飞

《中国工程科学》 2012年第14卷第7期页码 68-73

摘要：

为了提高BRT(bus rapid transit)专用道的利用率，基于车辆道路信息集成及协作技术，提出BRT专用道路权时分复用的车路协作方法，建立了BRT专用道时分复用的车路协作控制策略模型。研究了分段式BRT行程时间预测算法，结合实时交通流信息，建立车辆借还BRT专用道的换道时间模型，规划了车辆借还协作时序。实验表明，车辆协作控制策略中行程时间预测和借还时间估计接近实际值，并能够有效地实现专用道的时分复用，而不干扰BRT的优先运行。

关键词：车路集成环境车辆协作 BRT专用道时分复用换道时间模型

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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTION

《农业科学与工程前沿（英文）》 2021年第8卷第2期

摘要：

Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

关键词： Citrus / 2n gamete / interploidy hybridization / pericentromeric SNP marker / second division restitution

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OCDMA系统二维2D-OOSC方阵码的参数优化和性能分析

李传起,孙小菡,张明德,丁东

《中国工程科学》 2003年第5卷第4期页码 50-54

摘要：

给出了二维λ-t光正交方阵码2D-OOSC的设计方案, 重点讨论了2D-OOSC码字的相关性及码字参数对系统性能的影响。详细分析了2D-OOSC系统的用户容量以及由多用户干扰引起的误码性能。研究表明，在占用相同带宽的条件下，系统的用户容量远大于基于1D-OOC的WDM-CDMA混合系统，特别是在传输距离不太远的局域网中，光纤色散引起的传输损失较小。基于2D-OOSC地址码的 OCDMA系统有着现实的应用价值。

关键词：光码分多址（OCDMA）二维正交方阵码（2D-OOSC）多址干扰MUI 误码率（BER）

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Improved analytical model for residual stress prediction in orthogonal cutting

null

《机械工程前沿（英文）》 2014年第9卷第3期页码 249-256 doi: 10.1007/s11465-014-0310-1

摘要：

The analytical model of residual stress in orthogonal cutting proposed by Jiann is an important tool for residual stress prediction in orthogonal cutting. In application of the model, a problem of low precision of the surface residual stress prediction is found. By theoretical analysis, several shortages of Jiann’s model are picked out, including: inappropriate boundary conditions, unreasonable calculation method of thermal stress, ignorance of stress constraint and cyclic loading algorithm. These shortages may directly lead to the low precision of the surface residual stress prediction. To eliminate these shortages and make the prediction more accurate, an improved model is proposed. In this model, a new contact boundary condition between tool and workpiece is used to make it in accord with the real cutting process; an improved calculation method of thermal stress is adopted; a stress constraint is added according to the volume-constancy of plastic deformation; and the accumulative effect of the stresses during cyclic loading is considered. At last, an experiment for measuring residual stress in cutting AISI 1045 steel is conducted. Also, Jiann’s model and the improved model are simulated under the same conditions with cutting experiment. The comparisons show that the surface residual stresses predicted by the improved model is closer to the experimental results than the results predicted by Jiann’s model.

关键词： residual stress analytical model orthogonal cutting cutting force cutting temperature

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Machinability of damage-tolerant titanium alloy in orthogonal turn-milling

Tao SUN, Lufang QIN, Junming HOU, Yucan FU

《机械工程前沿（英文）》 2020年第15卷第3期页码 504-515 doi: 10.1007/s11465-020-0586-2

摘要： The damage-tolerant titanium alloy TC21 is used extensively in important parts of advanced aircraft because of its high strength and durability. However, cutting TC21 entails problems, such as high cutting temperature, high tool tip stress, rapid tool wear, and difficulty guaranteeing processing quality. Orthogonal turn-milling can be used to solve these problems. In this study, the machinability of TC21 in orthogonal turn-milling is investigated experimentally to optimize the cutting parameters of orthogonal turn-milling and improve the machining efficiency, tool life, and machining quality of TC21. The mechanism of the effect of turn-milling parameters on tool life is discussed, the relationship between each parameter and tool life is analyzed, and the failure process of a TiAlN-coated tool in turn-milling is explored. Experiments are conducted on the integrity of the machined surface (surface roughness, metallographic structure, and work hardening) by turn-milling, and how the parameters influence such integrity is analyzed. Then, reasonable cutting parameters for TC21 in orthogonal turn-milling are recommended. This study provides strong guidance for exploring the machinability of difficult-to-cut-materials in orthogonal turn-milling and improves the applicability of orthogonal turn-milling for such materials.

关键词： orthogonal turn-milling damage-tolerant titanium alloy tool life and failure machined surface integrity machinability

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Singularity loci of an orthogonal spherical two-degree-of-freedom parallel mechanism

Jialun YANG, Feng GAO,

《机械工程前沿（英文）》 2009年第4卷第4期页码 379-385 doi: 10.1007/s11465-009-0075-0

摘要： Singularity analysis plays an important role in the design of robots, especially for parallel robots. In this paper, the direct and inverse kinematics of an orthogonal spherical two-degree-of-freedom parallel mechanism is proposed based on the modified Euler angles. All the singular poses of the mechanism are achieved through the direct kinematic analysis. Self-motions, which are different from the general spherical 5 parallel mechanisms, are also discussed. Singularity loci in the joint space and Cartesian space are plotted according to the Jacobin of the mechanism. Result shows that the singularity loci at the joint space are two circles and one line, whereas at the Cartesian space are a circle.

关键词： 2-DOF orthogonal spherical parallel mechanism singularity loci self-motions

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Variable eccentric distance-based tool path generation for orthogonal turn-milling

Fangyu PENG,Wei WANG,Rong YAN,Xianyin DUAN,Bin LI

《机械工程前沿（英文）》 2015年第10卷第4期页码 352-366 doi: 10.1007/s11465-015-0361-y

摘要：

This study proposes an algorithm for maximizing strip width in orthogonal turn-milling based on variable eccentric distance. The machining error model is first established based on the local cutting profile at the contact line. The influencing factors of the strip width are then investigated to analyze their features and determine an optimizing strategy. The optimized model for maximum machining strip width is formulated by adopting a variable eccentric distance. Hausdorff distance and Fréchet distance are introduced in this study to implement the constraint function of the machining error in the optimized model. The computing procedure is subsequently provided. Simulations and experiments have been conducted to verify the effectiveness of the proposed algorithm.

关键词： orthogonal turn-milling variable eccentric distance local cutting profile machining strip-width maximization

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UNREDUCED MEGAGAMETOPHYTE FORMATION VIA SECOND DIVISION RESTITUTION CONTRIBUTES TO TETRAPLOID PRODUCTION

Qiangming XIA, Wei WANG, Kaidong XIE, Xiaomeng WU, Xiuxin DENG, Jude W. GROSSER, Wenwu GUO

《农业科学与工程前沿（英文）》页码 302-313 doi: 10.15302/J-FASE-2021385

摘要： Seedless fruits are desirable in the citrus fresh fruit market. Triploid production via diploid × tetraploid interploidy crosses is thought to be the most efficient and widely-used strategy for the breeding of seedless citrus. Although ‘Orah’ mandarin has desirable organoleptic qualities, seeds in the fruits weaken its market competitiveness. To produce new seedless cultivars that are similar to ‘Orah’ mandarin, we performed three 2x × 4x crosses using ‘Orah’ mandarin as the seed parent to regenerate triploid plantlets. A total of 182 triploid and 36 tetraploid plantlets were obtained. By analyzing their genetic origins using nine novel single nucleotide polymorphism (SNP) markers, all of the triploids and tetraploids derived from these three crosses were proven to be hybrids. Also, we demonstrated that 2n megagametophyte formation in ‘Orah’ mandarin result in tetraploid production in these three interploidy crosses. These tetraploid plantlets were genotyped using eight pericentromeric SNP markers and nine centromere distal SNP markers. Based on the genotypes of the 2n megagametophytes, the parental heterozygosity rates in 16 SNP loci and all 2n megagametophytes were less than 50%, indicating that second division restitution was the mechanism underlying 2n megagametophyte formation at both the population and individual levels. These triploid hybrids enrich the germplasm available for seedless breeding. Moreover, the tetraploid hybrids are valuable as parents for ploidy breeding for the production of seedless citrus fruits.

关键词： Citrus 2n gamete interploidy hybridization pericentromeric SNP marker second division restitution

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Control division of agricultural non-point source pollution at medium-sized watershed scale in Southeast

HUANG Jinliang, HONG Huasheng, ZHANG Luoping

《环境科学与工程前沿（英文）》 2008年第2卷第3期页码 333-339 doi: 10.1007/s11783-008-0035-7

摘要： This paper presents the study carried out for controlling agricultural non-point source pollution (NSP) in a medium-sized watershed covering 1.47 × 10 km in Southeast China using quantitative analysis coupled with geographic information system (GIS), universal soil loss equation (USLE), soil conservation service-curve number (SCS-CN), nutrient loss equations, and annualized agricultural nonpoint source model (AnnAGNPS). Based on the quantitative results derived from GIS and environmental models, five control division units were generated for NSP control in Jiulong River watershed, namely, controlling unit for soil losses, controlling unit for livestock breeding and soil losses, controlling unit for excessive fertilizer use and livestock breeding, controlling unit for soil losses and fertilizer use, and controlling unit for excessive fertilizer use and soil losses. This study proved that integrating GIS with environmental models can be adopted to efficiently evaluate major sources and contributors of NSP, and identify the critical source areas of NSP, which enables adjusting measures to local conditions by further control division units developed through such study for control and management of water quality degradation induced by NSP in the Jiulong River watershed.

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SUSTAINABLE PLANT PEST MANAGEMENT THROUGH OPTIMIZATION AND MINIMIZATION

Plant Production and Protection Division (NSP), Food and Agriculture Organization of the United Nations

《农业科学与工程前沿（英文）》 2022年第9卷第1期页码 161-166 doi: 10.15302/J-FASE-2021426

摘要：

Plant pests and diseases have significant negative impacts on global food security, world trade and rural livelihoods. Climate change exacerbates these impacts in certain parts of the world. Overreliance on pesticides as the primary tool for plant pest management leads to problems such as pesticide resistance and pest resurgence. Environmental and food safety concerns are also associated with overuse of pesticides in crop production. There is clearly a need for a shift in pest management strategies and practices globally. Optimization of structures and functions in crop production agroecosystems through soil conservation practices and cropping diversification can improve pest regulation services provided in the systems. Prioritization of safer alternatives and practices in the IPM pyramid, such as resistant varieties and biopesticides, helps minimize the use of potentially risky agricultural inputs such as synthetic pesticides. Investment is needed to boost the development of innovative green technologies and practices. Production, distribution, use and regulatory capacities need to be strengthened to facilitate large-scale adoption of green technologies and practices. Finally, policy, financial and market instruments should be wielded to provide an enabling environment for the transformation to sustainable plant pest and disease management strategies and practices worldwide.

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标题作者时间类型操作

一种通过循环前缀再利用改善OFDM系统带宽的新型节能ICI消除技术

Sandeep SAROWA, Harmanjeet SINGH, Sunil AGRAWAL, B. S. SOHI

期刊论文

分层空时码多载波CDMA的译码与检测

杨洁,酆广增

期刊论文

OFDM直接变频接收机中通用的I/Q不平衡估计与补偿方法

Fang-lin GU, Shan WANG, Wen-wu WANG

期刊论文

基于非完美信道状态的下行OFDMA系统中优化物理层安全问题的资源分配算法研究