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.

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。

“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。

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。

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。

艰险山区阵列式三维音频大地电磁勘探方法与应用

艰险山区是铁路工程勘探领域的重难点。地球物理方法具有设备轻便、施工效率高、成果直观的特点,适合艰险山区的探测工作。大跨度硐室横向范围宽,单条物探测线难以满足勘探精度要求。为此,本文介绍了适用于艰险山区大跨度硐室勘察的阵列式三维音频大地电磁勘探方法,该方法测线布置综合考虑了隧道埋深、硐室跨度,以及测点分布均匀性和边缘效应对探测精度的影响,有效提高了外业资料质量,通过联合反演构建了详实的地下三维视电阻率数据体,可直观反映地下地质体异常空间展布情况。研究成果有效揭示了破碎富水岩体地下空间赋存形态,为隧道施工设计提供了参考。

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。

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。

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。

基于数字孪生的电机基座码垛线虚拟调试技术研究

针对PLC和ABB工业机器人联合控制的生产系统现场调试成本高、仿真平台难以驱动机器人仿真等问题,以电机基座码垛线为研究对象,提出一种基于仿真平台NX MCD的电机基座码垛线虚拟调试方法。首先,基于数字孪生技术在NX MCD中构建产线的仿真模型;其次,设计虚拟调试方案的通信框架,主要利用C#语言并基于PC SDK对机器人仿真器进行二次开发以实现对机器人的控制和数据读取;最后,利用OPC UA技术完成PLC控制、机器人控制和NX MCD模型之间信号和数据的实时传输和反馈,完成产线联合调试。仿真结果表明:基于NX MCD的电机基座码垛线虚拟调试方案可行,能及时规避产线缺陷,缩短调试周期,降低开发成本。

综合测绘在海上风电电缆后保护施工中的应用

为提升海上风电场风机间非掩埋电缆后保护施工的作业效率,降低施工成本,综合运用多波束技术和侧扫声呐技术,对非掩埋电缆后保护施工作业区进行精确的地形地貌测绘。根据测绘结果,结合MS1000成像声呐和船舶定位与超短基线水下定位技术,监控和定位液压释放架布放混凝土联锁排,对非掩埋电缆进行后保护施工作业。实际应用结果表明,该施工技术能提高布放混凝土联锁排的作业效率,降低施工成本,取得良好的社会和经济效益。

流动注射法检测枸杞中二氧化硫残留量的方法比较及风险评估

近年来自动化检测设备以及对应方法相继涌现,本研究使用在线蒸馏-流动注射法与国标中酸碱滴定法、离子色谱法对枸杞中二氧化硫残留量进行检测比较。结果表明,三种方法的测定结果并无显著性差异。在线蒸馏-流动注射法RSD在1.5%~2.4%之间,加标回收率在86.1%~92.7%之间,因其具有自动化程度高、检测周期短的优势,更适合大批量样品的快速准确检测。用在线蒸馏-流动注射法对106批次红枸杞中的二氧化硫残留量进行检测分析,并对枸杞中的二氧化硫残留量进行暴露风险评估。结果显示,二氧化硫超标率达21.7%,枸杞中二氧化硫残留尚未对健康构成威胁。

“雨露均沾”抑或“强强联合”:衔接过渡期驻村帮扶资源配置逻辑及其实践后果

驻村帮扶是衔接过渡期巩固好脱贫成果、接续推进乡村振兴的重要制度支撑。通过对西部地区两县驻村帮扶工作的调查研究发现,与脱贫攻坚时期更加注重全面帮扶的“雨露均沾”不同,衔接过渡期驻村帮扶资源配置更加注重“强强联合”,在乡村振兴示范点创建的工作机制与目标指引下,一些重点乡村建设项目和资源被少数优势村庄捕获,驻村帮扶强势主客体间存在着理性的“共同谋划”,而部分弱势村庄则深陷于自身基础薄弱和外来资源稀缺的两难境地。驻村帮扶主客体的“强强联合”在一定程度上导致了驻村帮扶主体的行为偏差、村际水平上新的不公平、制度效能低下与低水平管理困境等后果。因此,应加快构建驻村帮扶资源的精准匹配与县域资源统筹共享机制,拓展资源供给渠道并优化驻派结构,以提升帮扶资源配置的公平性和整体帮扶效能。