A Dynamic Model of Heavy Ion ~7Li Irradiation Mutagenesis Based on Maize Inbred Line Nutrition Difference

To reveal the saddle-type dose effect relationship, we propose a radiation mutagenesis model based on maize nutrition difference resulting from heavy ion ~7Li radiation. Through irradiation mutagenesis, apparent trait selection, amino acids and fatty acids content determination, and modeling, dynamic evolution from microscopic damage and repair initiation to the final macroscopic biological effects are considered simultaneously. The results show that the steady state nature is independent of evolution time and only relates to different radiation doses.Heavy ion ~7Li radiation could effectively cause maize phenotypic variation and could improve nutritional quality.This model not only gives a good fit to the experimental results on most types of amino acids and fatty acids, but also offers an adequate explanation of the experimental phenomenon underlying the saddle-type bimodal dose effect. By combining experimental results with theoretical analyses, we suggest that the synergy of the stimulus effect and momentum transfer is the main cause of the saddle-type dose effect bimodal curve. This provides an effective strategy for conducting maize germplasm innovation.

A new investigation on drift of base-line value in geomagnetic observation

A new explanation on drift of base line (BL) value in geomagnetic observation was presented by means of detailed analysis on BL value of H variometer at Tianshui Observatory from 1991 to 1995, in association with some numerical simulation. It was confirmed that drift does not always exist. For variometers running normally for many years, drift appears to be zero. The temperature dependence of BL value is reversible below a certain temperature but irreversible above it. This irreversibility is the main reason that causes the BL value to show a monotonous declination with time, which has been mistaken for the drift in the past. As to the H variometer at Tianshui Observatory, no drift exists in BL value in these years. A new method was introduced to study the BL value variation with temperature by separating it into three parts.

Formulation Method and Management Principle for the Safety Base-line of Atmospheric Environmental Quality

The formulation of the safety base-line for atmospheric environmental quality is not only basic needs of mankind maintaining the quality of survival environment but also concrete measures of red line system for national ecological protection. It is urgent to solve the problem in current environmental management how to draft the safety basa-line of atmospheric environmental quality. To solve this problem, the connotation of safety base-line for atmospheric environmental quality is defined firstly, and then the indexes for atmospheric importance, sensitivity and vulnerability are generalized. Moreover, formulation methods for red, yellow and green lines of the safety base-line for atmospheric environmental quality are put forward ,and corresponding division principle and management principle are put forward finally.

Vision-based Localization from Three-Line Structures (TLS)

This paper presents a novel vision based localization algorithm from three-line structure ( TLS) .Two types of TLS are investigated: 1) three parallel lines ( Structure I) ; 2) two parallel lines and one orthogonal line ( Structure II) .From single image of either structure,the camera pose can be uniquely computed for vision localization.Contributions of this paper are as follows: 1 ) both TLS structures can be used as simple and practical landmarks,which are widely available in daily life; 2) the proposed algorithm complements existing localization methods,which usually use complex landmarks,especially in the partial blockage conditions; 3) compared with the general Perspective-3-Lines ( P3L) problem,camera pose can be uniquely computed from either structure.The proposed algorithm has been tested with both simulation and real image data.For a typical simulated indoor condition ( 75 cm-size landmark,less than 7.0 m landmark-to-camera distance,and 0.5-pixel image noises) ,the means of localization errors from Structure I and Structure II are less than 3.0 cm.And the standard deviations are less than 3.0 cm and 1.5 cm,respectively.The algorithm is further validated with two actual image experiments.Within a 7.5 m × 7.5 m indoor situation,the overall relative localization errors from Structure I and Structure II are less than 2.2% and 2.3% ,respectively,with about 6.0 m distance.The results demonstrate that the algorithm works well for practical vision localization.

The Line Shape of Double-Sided Tooth-Disk Waveguide Filters Based on Plasmon-Induced Transparency

We numerically investigate a coupled-resonator structure consisting of a stub resonator and a nanodisk resonator using a two-dimensional finite element method. Simulation results show that plasmon-induced transparency （PIT） occurs in the transmission spectra, and the sharp asymmetric Fano lines increase the sensitivity to 1.4 ×10^3 nm/RIU. We also analyze the properties of the structure with different radii of the nanodisk and the length of the tooth cavity. Moreover, we find that the PIP only happens when the staggered system is around a fixed location with different separate distances, which is not similar to the previous researches. Our model may be important to photonic-integrated circuits and the sensitivity in sensors.

Effective Hybrid Teaching-learning-based Optimization Algorithm for Balancing Two-sided Assembly Lines with Multiple Constraints

Due to the NP-hardness of the two-sided assembly line balancing （TALB） problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints （TALB-MC）. Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization （TLBO） algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost fimction. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search （VNS） is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm （LAHC） for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.

On-line Detection of Gas Pipeline Based on the Real-Time Algorithm and Network Technology with Robot

The detection system integrates control technology, network technology, video encoding and decoding, video transmiss-ion, multi-single chip microcomputer communication, dat-abase technology, computer software and robot technology. The robot can adaptively adjust its status according to diameter (from 400 mm to 650 mm) of pipeline. The maximum detection distance is up to 1 000 m. The method of video coding in the system is based on fractal transformation. The experiments show that the coding scheme is fast and good PSNR. The precision of on-line detection is up to 3% thickness of pipeline wall. The robot can also have a high precision of location up to 0.03 m. The control method is based on network and characterized by on-line and real-time. The experiment in real gas pipeline shows that the performance of the detection system is good.

内陆清洁能源基地±800kV/10000MW直流外送拓扑设计

大力开发大规模清洁能源基地是国家“十四五”现代能源体系规划明确的重点任务。针对藏东南地区大规模水电、光伏送出场景,计及新能源基地海拔高、输电走廊受限问题,设计了±800 kV/10000 MW多直流电压等级混合直流、多直流电压等级柔直和四端混合直流系统送出拓扑。针对沙戈荒地区风电、光伏送出场景,设计了±800 kV/10000 MW三端柔直、四端柔直和多直流电压等级混合直流系统送出拓扑。最后,在PSCAD/EMTDC仿真平台搭建了各拓扑方案的仿真模型,对比分析了各拓扑的技术特点。通过研究,以期为未来相关工程实践拓扑设计提供参考。

内水渗漏软化基底对盾构隧洞衬砌管片受力性能的影响分析

水工盾构隧洞在运行过程中存在内水渗漏导致基底软化的风险,基底软化将对隧洞管片受力变形产生影响。依托实际水工盾构隧洞工程,构建了由管片、灌浆体和围岩组成的三维有限元数值模型,针对Ⅴ类围岩条件下因渗漏导致基底均匀和不均匀软化的状况,研究了管片的受力性能变化规律。结果表明:在内外荷载作用下,管片的环向应力、竖向位移和定位销应力均随基底软化深度的增加而增大,均匀软化条件下仰拱管片出现峰值为1.88 MPa的拉应力,存在管片开裂风险;基底软化导致定位销应力增大,而管片竖向位移的变化幅度较小。研究成果可为水工盾构隧洞的安全运行监测提供科学依据。

“三水”统筹的流域水生态环境分区管控技术与实践

基于“三水”(水生态、水环境、水资源)统筹,开展流域空间精细化管控对推进新时代流域协同保护与治理具有重要意义。按照“‘三水’问题识别—‘三水’分区划定—质量目标确定—管控单元集成”的思路,构建了流域水生态环境分区管控技术方法。以白洋淀流域为实践对象,识别出流域性突出生态环境问题;衔接现有水生态环境管理分区与政策要求,划定生态保护红线、环境质量底线及资源利用上线;明确“三水”分区域差异化生态环境管理目标与资源环境承载约束,聚类叠“三水”分区并综合划定水生态环境综合管控单元、制定结构化生态环境准入清单。

基于电子式电压互感器边界特性分析的35 kV配网输电线路单端暂态量保护方案及其整定

随着分布式电源广泛接入配电网,传统三段式电流保护方案的性能严重劣化。单端暂态量边界保护由于具备不依赖电源特性等突出优势,有望成为改善主动配电网保护配置性能的有效方案,但其需依附于线路边界强健的滤波作用。为此,该文研究发现,可利用智能变电站和智能开闭所中电子式电压互感器、金属氧化物避雷器与其余设备杂散电容共同作为线路边界,其优异的高频滤波作用能够为暂态量保护方案的设计奠定基础;其次,利用区内外故障时电压行波高频频带能量差异构造保护判据,并基于整定门槛与动作时序的合理配合形成单端暂态量阶段式保护方案;最后,基于PSCAD仿真平台验证所提方案的有效性、灵敏性与可靠性,其可与电流保护方案协同互济以强化主动配电网继电保护方案的动作性能。

新能源风力发电项目66 kV系统应用前景研究

随着“3060”碳达峰、碳中和目标的实施,大容量风电基地将不断出现,未来风电机组单机容量越来越大,集电线路采用66 kV电压等级,由于其在投资和电能损耗方面的优势,将是风电场发展的必然趋势。文章对35 kV与66 kV集电线路的经济性进行分析,以期为相关人员提供参考。

基于高岭土增韧环氧树脂水泥基材料的多强度组合指标配比优化法

煅烧高岭土能有效改善环氧树脂水泥基材料的力学性能,实验表明:煅烧高岭土可大大提高环氧树脂水泥基材料的3 d早期抗折、抗压强度,当高岭土掺量为30%时,改性环氧树脂水泥基材料的抗折及抗压强度分别提高了134.28%、106.25%;当高岭土掺量小于30%时,改性环氧树脂水泥基材料具有二次抗折强度,且抗折强度残余率大于50%。根据不同高岭土掺量对改性环氧树脂水泥基材料抗压强度、抗折强度、二次抗折强度的影响规律,提出了适用于不同结构工程受力特点的多强度组合指标配比优化法,获得了考虑二次抗拉强度影响的不同最大拉应力和最大压应力组合条件下最优的高岭土配比,为实际不同结构体不同部位不同受力特征的高岭土改性环氧树脂水泥基材料制备提供了理论依据。

水环境样品体外生物测试效应触发值的研究进展

水环境样品综合毒性的体外生物测试可以直接获得水环境中众多污染物共存状态下的生物毒害信息,已成为水环境污染评估和诊断的重要手段之一。但由于目前没有用于判定水质优劣的毒性效应限值标准,导致其很难被用于水质管理。为此,越来越多的研究聚焦于推导体外生物测试的效应触发值(effect-based trigger value,EBT)。本文综述了EBT建立的背景和推导原则,并总结了以健康保护为目标和以生态保护为目标的多种EBT推导方法,其中针对饮用水水质的EBT以保护人体健康为前提,主要基于每日容许摄入量(allowable daily intake,ADI)、体内安全浓度、癌症发病率增加10%的每日剂量(TD10)和环境质量标准(environmental quality standard,EQS)中的水质指导值(guideline value,GV)推导,针对地表水的EBT以生态保护为目标,依据地表水EQS中的GV值和物种敏感度分布(SSD)曲线中的第5个百分位数的危险浓度(hazardous concentration,HC5)推导。本文系统比较了不同方法推导出的体外生物测试EBT值和特征,总结了EBT在水环境中的应用,以期为高通量体外生物测试用于水质评估提供理论依据和技术支撑。

基于ARM和FPGA的数字多道分析器研制

多道分析器作为γ能谱测量中不可或缺的组件,其性能直接影响能谱仪分辨率及测量精度,传统的多道分析器多采用模拟电路方法或使用数字采集卡实现。模拟多道对于影响能谱仪性能的成形时间、脉冲通过率及死区时间修正等问题上具有一定的局限性,而这会直接影响能谱分析结果;数字采集卡是实现数字采集的计算机扩展卡,成本较高,不利于市场化推广。数字多道分析器对脉冲信号进行全数字采样,将其转化为数字量,利用数字信号处理方法,通过软件实现,完成整个信号分析处理过程,可极大提高系统稳定性与可靠性,相比于前两种方案,优势明显。设计了一款数字多道分析器,采用ARM处理器+高速ADC+FPGA的硬件方案,主要包括AD采样模块、FPGA数据处理模块和以STM32F4为核心的控制和通信模块。使用数字信号处理方法,编写硬件描述代码实现了脉冲信号滤波成型、幅值提取和基线修正等核脉冲处理的关键算法,最后给出探测器核信号经本文设计的数字多道处理后的γ能谱图。根据国内外研究成果及理论基础,经过深入系统理论分析,方法仿真验证,以及实际调试过程,最终研制出一款可商业化实用、完整且高精度的数字多道分析器,并将其应用在低本底γ能谱仪上,其能量分辨率测试均值为6.6791%,能量线性相关度R2在0.9999以上,积分非线性为0.26%。设计的数字化多道分析器采用ARM+FPGA的方式,极大程度降低了系统设计难度和成本,实现了高精度、高速的脉冲信号数字化,测试性能可达到数字采集卡的水平,具有极高的市场应用价值。

基于集成树和MoE的馈线统计线损率双层估计模型

统计线损率是衡量电力系统经济运行的重要指标。然而,用户用电数据采集异常、数据传输中断等因素会导致统计线损率异常或缺失,这严重阻碍了智能配电网的线损精益化管理与经济高效运行。针对馈线统计线损率合理值的估计问题,该文提出了一种基于集成树和混合专家系统(MoE)的馈线统计线损率双层估计模型。首先,使用最大信息系数以更有效地分析统计线损率与其相关特征间的非线性关系,并采用鲁棒性强的K-Medoids聚类算法对馈线进行精细划分;然后,使用Stacking集成学习框架,基于基估计和元估计双层模型对馈线统计线损率进行两阶段估计,选用决策树和各类集成树模型作为基估计模型对统计线损率进行初步估计,将各基估计模型输出结果输入元估计模型MoE中进行最终估计,使用方均根误差(RMSE)和平均绝对误差(MAE)来衡量模型所估计统计线损率的合理性;最后,通过算例分析表明,与其他模型相比,该文所提馈线统计线损率双层估计模型具有更低的RMSE和MAE,对馈线统计线损率的估计效果更好。

OBE理念融入课程思政构建基础医学总论的效果初探

基于社会需求以培养德才兼备的医学生为成果导向教育(outcome-based education,OBE)融入课程思政构建基础医学总论提供了基础。基础医学总论是内蒙古医科大学五年制临床医学专业卓越医师教改班开设的第一门基础医学课程,具有学时多,教学内容多且不系统,课程难度大的特性。以线上和线下教学平台为载体,基于OBE理念融入课程思政以调整教学方法和手段,为国家培养能肩负“健康所系、性命相托”职责的医学人才,使医学生既具有精湛的医技,还具有“敬畏生命、仁爱至善、坚韧尚行”的医者精神。基于OBE理念融入课程思政构建基础医学总论,克服了学生的学习畏难情绪,增强了教学效果,利于培养德才兼备的医学生。本研究可为今后医学课程教学改革提供参考。

弃陇入川:三线建设初期062基地调迁研究

三线建设初期,由于对工程项目的进程要求过快、过急,普遍存在项目选址未经严格科学论证便匆匆确定的现象,曾造成严重的经济损失.062基地是我国三线建设中唯一从事远程运载火箭科研生产工程.它从建址甘肃天水再到调迁四川达县,前后不到一年时间,造成了人力、物力、财力的巨大浪费.其根本原因在于它明显违背国家制定的基本建设程序.三线建设中,这种“边定点、边勘测、边施工”的原则,不仅风险很大,而且不可避免地会酿成严重后果.

基于改进差分进化的线路故障诊断混合模型

针对输电线路故障诊断问题,提出了一种改进差分进化和峰值密度聚类的线路故障混合诊断模型。首先,提出一种由录波测距模型和改进的线路故障案例推理(lines fault case-based reasoning,LFCBR)模型构成的故障距离混合预测模型;其次,为提高案例推理模型的精度,提出一种利用个体精度优化的改进差分进化算法,以优化不同模态内的案例推理过程中的属性权重;最后,结合密度峰值聚类和相似度算法更新案例库中的源案例,以便更好地维护案例。实验结果表明,所提算法的性能优于线性回归和遗传案例推理(linear regression and genetic case reasoning,LRGCR)法、最近邻策略考察(nearest neighbor investigation strategy,NNIS)法、案例推理、录波测距算法的预测效果,在国网某供电公司获得了较好的效果。