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Analysis and Simulation of the Influence of Electromagnetic Fields on Living Beings near HV Power Lines Using the FDTD Method
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作者 Anthony Bassesuka Sandoka Nzao 《Open Journal of Applied Sciences》 2023年第12期2343-2359,共17页
Recent decades have seen rapid advances in the field of electrical engineering, such that our environment has become a sea of electrical and magnetic signals, raising questions about the possible effects of low-freque... Recent decades have seen rapid advances in the field of electrical engineering, such that our environment has become a sea of electrical and magnetic signals, raising questions about the possible effects of low-frequency electromagnetic fields on the environment and which are capable of modifying and destroying our ecosystem. Particular interest was given in this article due to a massive influx of population living near high voltage lines. The analysis and simulation of the influence of low frequency electromagnetic fields on living beings in the vicinity of high voltage sources 132 kV and 220 kV in urban areas in DR Congo is the subject of our research with a view to estimating the level of exposure of humans to low frequency electromagnetic fields. To carry out our research, we used the classic method of analyzing the field produced near a high voltage line based on Maxwell’s image theory, the Maxwell-Gauss theorem and Maxwell-Ampère theorem to model and quantify low-frequency electromagnetic fields in the vicinity of high-voltage lines. The 2D FDTD numerical formulation was developed from telegraphers’ equations and allowed us to obtain models of current and voltage induced by electromagnetic fields on living beings below and near HV lines. The different simulations carried out on the proposed models illustrate the effects of the electrical and geometric parameters of the pylons on the distribution of the electromagnetic field in the vicinity of the HV lines. The results obtained were compared to the safety limits recommended by the standards. 展开更多
关键词 Low Frequency Electromagnetic Field Modeling Field and Health Maxwell’s Equations FDTD Method Electromagnetic Compatibility High Voltage line
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Characterization of Reverse Thermo-sensitive Genic Male Sterile Lines in Cold Regions of China
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作者 高扬 谭炎宁 +2 位作者 孟昭河 段美娟 徐秋生 《Agricultural Science & Technology》 CAS 2017年第7期1183-1186,1201,共5页
Yannong S, a reverse thermo-sensitive genic male sterile (TGMS) line, is sterile at high temperature and fertile at low temperature. In the present study, the fertility of Yannong S and the japonica reverse TGMS lin... Yannong S, a reverse thermo-sensitive genic male sterile (TGMS) line, is sterile at high temperature and fertile at low temperature. In the present study, the fertility of Yannong S and the japonica reverse TGMS lines derived from it was in- vestigated in Harbin, Heilongjiang from 2013 to 2015. The results showed that Yan- nong S was completely male sterile in July and August (the hottest months of the year in Harbin), and the seed setting rate of bagged panicles was 0. We also in- ferred that the critical temperature for inducing the sterility of Yannong S was higher than 28 ℃. Most of the japonica reverse TGMS lines derived from Yannong S were completely aborted in July and August, with a seed setting rate of 0. It can be con- cluded that the reverse TGMS lines derived from Yannong S are genetically stable lines that have a long period of sterility in cold regions, so they may be the ideal genetic materials for the development and in-situ seed production of japonica hybrid rice. 展开更多
关键词 Japonica hybrid rice Reverse thermo-sensitive genic male sterile lines Cold regions Yannong s FERTILITY
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S Zorb装置反应器接收器脱气线和再生器取热盘管改造
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作者 张伟 《炼油技术与工程》 CAS 2024年第5期29-32,共4页
某公司对S Zorb装置首个运行周期内出现的反应器接收器脱气线泄漏、再生器取热盘管泄漏等运行问题开展了技术攻关,提出了工艺优化调整、工程技术改造建议。2019年大检修时对反应器脱气线进行扩径,由DN100扩径为DN150,控制气提量小于670 ... 某公司对S Zorb装置首个运行周期内出现的反应器接收器脱气线泄漏、再生器取热盘管泄漏等运行问题开展了技术攻关,提出了工艺优化调整、工程技术改造建议。2019年大检修时对反应器脱气线进行扩径,由DN100扩径为DN150,控制气提量小于670 m^(3)/h,对再生系统取热蒸汽和再生风流控阀等进行了工程技术改造。第二运行周期未出现脱气线减薄泄漏和再生器取热盘管泄漏问题。2023年6月大检修时对上次大检修改造部位进行检查以验证工程改造的有效性,经全面检查,确认脱气线内部未发现冲刷痕迹,再生器取热盘管打压合格,外观正常,证明改造措施有效,可以满足“四年一修”目标要求。 展开更多
关键词 s Zorb装置 反应器接收器 脱气线 再生器 取热盘管 泄漏 冲刷腐蚀 高频振荡
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Numerical Modeling and Computer Simulation of a Meander Line Antenna for Alzheimer’s Disease Treatment, a Feasibility Study
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作者 Felipe P. Perez Maryam Rahmani +8 位作者 Jorge Morisaki Farhan Amran Syazwani Bakri Akmal Halim Alston Dsouza Nurafifi Mohd Yusuff Amran Farhan James Maulucci Maher Rizkalla 《Journal of Biosciences and Medicines》 CAS 2023年第2期177-185,共9页
Alzheimer’s disease (AD) is a brain disorder that eventually causes memory loss and the ability to perform simple cognitive functions;research efforts within pharmaceuticals and other medical treatments have minimal ... Alzheimer’s disease (AD) is a brain disorder that eventually causes memory loss and the ability to perform simple cognitive functions;research efforts within pharmaceuticals and other medical treatments have minimal impact on the disease. Our preliminary biological studies showed that Repeated Electromagnetic Field Stimulation (REFMS) applying an EM frequency of 64 MHz and a specific absorption rate (SAR) of 0.4 - 0.9 W/kg decrease the level of amyloid-β peptides (Aβ), which is the most likely etiology of AD. This study emphasizes uniform E/H field and SAR distribution with adequate penetration depth penetration through multiple human head layers driven with low input power for safety treatments. In this work, we performed numerical modeling and computer simulations of a portable Meander Line antenna (MLA) to achieve the required EMF parameters to treat AD. The MLA device features a low cost, small size, wide bandwidth, and the ability to integrate into a portable system. This study utilized a High-Frequency Simulation System (HFSS) in the design of the MLA with the desired characteristics suited for AD treatment in humans. The team designed a 24-turn antenna with a 60 cm length and 25 cm width and achieved the required resonant frequency of 64 MHz. Here we used two numerical human head phantoms to test the antenna, the MIDA and spherical head phantom with six and seven tissue layers, respectively. The antenna was fed from a 50-Watt input source to obtain the SAR of 0.6 W/kg requirement in the center of the simulated brain tissue layer. We found that the E/H field and SAR distribution produced was not homogeneous;there were areas of high SAR values close to the antenna transmitter, also areas of low SAR value far away from the antenna. This paper details the antenna parameters, the scattering parameters response, the efficiency response, and the E and H field distribution;we presented the computer simulation results and discussed future work for a practical model. 展开更多
关键词 Alzheimer’s Disease Meander line Antenna HFss EMF linearity sAR Field Distribution
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General Analytic Solution of the Telegrapher’s Equations and the Resulting Consequences for Electrically Short Transmission Lines 被引量:1
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作者 Steffen Kü hn 《Journal of Electromagnetic Analysis and Applications》 2020年第6期71-87,共17页
Based on classical circuit theory, this article develops a general analytic solution of the telegrapher’s equations, in which the length of the cable is explicitly contained as a freely adjustable parameter. For this... Based on classical circuit theory, this article develops a general analytic solution of the telegrapher’s equations, in which the length of the cable is explicitly contained as a freely adjustable parameter. For this reason, the solution is also applicable to electrically short cables. Such a model has become indispensable because a few months ago, it was experimentally shown that voltage fluctuations in ordinary but electrically short copper lines move at signal velocities that are significantly higher than the speed of light in a vacuum. This finding contradicts the statements of the special theory of relativity but not, as is shown here, the fundamental principles of electrical engineering. Based on the general transfer function of a transmission line, the article shows mathematically that an unterminated, electrically short cable has the characteristics of an ideal delay element, meaning that an input signal appears at the output with a slight delay but remains otherwise unchanged. Even for conventional cables, the time constants can be so small that the corresponding signal velocities can significantly exceed the speed of light in a vacuum. The article also analyses the technical means with which this effect can be conveyed to very long cables. 展开更多
关键词 Telegrapher’s Equations Transmission line Theory special Theory of Relativity Electrically short Transmission lines FTL Communication
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基于YOLOv5s的轻量化架空输电线路鸟巢检测网络
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作者 徐业东 蔡亚恒 +2 位作者 李严 刘学雷 曹英丽 《电子测量技术》 北大核心 2024年第7期138-148,共11页
架空输电线路上的鸟巢侵占会对铁塔上的电力设备造成安全隐患,间接可能影响整个电力系统的稳定运行。针对目前架空输电线路鸟巢检测模型在复杂场景以及小目标场景下检测精度不高,检测效率低,模型复杂等问题。本研究提出一种基于YOLOv5s... 架空输电线路上的鸟巢侵占会对铁塔上的电力设备造成安全隐患,间接可能影响整个电力系统的稳定运行。针对目前架空输电线路鸟巢检测模型在复杂场景以及小目标场景下检测精度不高,检测效率低,模型复杂等问题。本研究提出一种基于YOLOv5s框架的轻量化架空输电线路鸟巢检测网络。首先在主干部分采用Fasternet重构YOLOv5s特征提取网络,降低模型复杂度,提高运行速度;然后在特征融合网络部分嵌入ConvMixer层,ConvMixer层的结构设计有助于在特征信息中更好的捕捉空间和通道的关系,提升模型对于小目标的检测能力;最后在特征融合网络部分引入ODConv模块,令送入检测头的特征图包含更多有效特征,提高模型对复杂场景和小目标的检测性能。实验结果表明,本文与基线模型YOLOv5s相比,计算量和模型体积分别减少了86%和72%,平均精度均值达到96.4%,检测速度达到104.2帧/s,验证了本文改进模型的有效性和可行性。 展开更多
关键词 轻量化 架空输电线路 YOLOv5s 鸟巢 目标检测
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基于TDLAS的H_(2)S高温反应特性实验研究
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作者 王嘉琦 田思迪 +3 位作者 高东波 田志伟 彭志敏 杜艳君 《热力发电》 CAS CSCD 北大核心 2024年第2期162-169,共8页
电站锅炉在低NO_(x)燃烧过程中因锅炉内还原性气氛浓度较高,会产生较多H_(2)S气体。针对H_(2)S因具有易燃、强腐蚀性、剧毒性而可能对火电厂造成多种危害的问题,采用可调谐二极管激光吸收光谱(tunable diode laser absorption spectrosc... 电站锅炉在低NO_(x)燃烧过程中因锅炉内还原性气氛浓度较高,会产生较多H_(2)S气体。针对H_(2)S因具有易燃、强腐蚀性、剧毒性而可能对火电厂造成多种危害的问题,采用可调谐二极管激光吸收光谱(tunable diode laser absorption spectroscopy,TDLAS)方法结合多通池和计算机搭建低气体摩尔分数在线测量系统,实现了对混合气体中摩尔分数在10–6量级H_(2)S的精确在线测量,并利用该测量系统进行了H_(2)S高温反应实验,探究实验温度和混合气体中O_(2)摩尔分数对该反应的影响。实验结果展示了压力为80 kPa、O_(2)摩尔分数为0~5%的条件下,H_(2)S开始发生化学反应的温度随O_(2)摩尔分数变化的变化规律,整体而言,混合气体中O_(2)摩尔分数越高,H_(2)S开始发生化学反应的温度越低。实验结果可以为锅炉烟气中H_(2)S的生成、转化和危害控制提供一定数据基础。 展开更多
关键词 TDLAs H_(2)s 在线测量 高温反应 O_(2)摩尔分数
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基于改进HybridNets的多任务驾驶感知方法
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作者 武鹏宇 张远辉 刘康 《激光杂志》 CAS 北大核心 2024年第10期80-85,共6页
针对计算资源有限的自动驾驶系统和多任务驾驶感知算法精度低问题,提出了一种改进的HybridNets多任务驾驶感知算法。选择EfficientNetV2-S作为该算法的主干网络,降低参数数量,提高训练速度和识别准确率;结合深度可分离卷积并采用shuffle... 针对计算资源有限的自动驾驶系统和多任务驾驶感知算法精度低问题,提出了一种改进的HybridNets多任务驾驶感知算法。选择EfficientNetV2-S作为该算法的主干网络,降低参数数量,提高训练速度和识别准确率;结合深度可分离卷积并采用shuffle-channel方式卷积降低模型计算量;使用三个独立的解码器来解决不同难度的问题,并在主干网络与Neck端之间加入A2-Nets双重注意力机块,充分提取全局特征。与基础网络HybridNets相比,该模型在车辆检测任务中mAP50可达79.8%,提高了2.6%;可行驶区域分割任务中mIoU可达91.8%,提高了1.2%;车道线检测任务中IoU可达32.55%,提高了0.93%。运行速度达到38 FPS。实验结果表明,与现有方法相比,所提方法的准确率有较大提高。 展开更多
关键词 EfficientNetV2-s A2-Nets 目标检测 驾驶区域分割 车道线检测
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城市轨道交通S型曲线夹直线与长直线地段振动对比试验研究
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作者 张明凯 赵炎南 +2 位作者 许以凯 赵才友 易强 《噪声与振动控制》 CSCD 北大核心 2024年第2期178-184,共7页
夹直线在一定程度上可以保证线型连续和行车平顺,但过短的夹直线长度会导致振动叠加,影响旅客舒适度和列车运行的稳定性,增加运营维护成本。本文通过对城市轨道交通S型曲线夹直线与长直线地段振动对比试验研究,从时域、时频域、振动加... 夹直线在一定程度上可以保证线型连续和行车平顺,但过短的夹直线长度会导致振动叠加,影响旅客舒适度和列车运行的稳定性,增加运营维护成本。本文通过对城市轨道交通S型曲线夹直线与长直线地段振动对比试验研究,从时域、时频域、振动加速度级及地面Z振级等方面对获得的数据进行分析,解释了夹直线段振动叠加的产生机理,验证了车体垂向加速度峰值在缓直点处会出现峰值提前现象,并阐述了夹直线段的振动叠加现象对地面环境振动的影响。结论如下:车辆在通过S型曲线线形变化点时产生的冲击振动会通过钢轨以弹性波的形式向前传播,与车辆在夹直线段行驶产生的振动叠加;由于弹性波的形式传播的速度远高于车辆行驶速度,因此会导致夹直线段出现振动加速度峰值提前现象;S型曲线夹直线的垂向振动加速度的优势频率要高于长直线段,且更向高频分散;S型曲线夹直线产生的振动叠加现象不会对地面环境振动产生影响。 展开更多
关键词 振动与波 地铁 s型曲线夹直线 试验研究 环境振动 弹性波
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CHARACTERISTIC IMPEDANCE OF SPECIFIC TRANSMISSION LINES WITH OFFSET INNER CONDUCTORS
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作者 马西奎 《Journal of Electronics(China)》 1990年第3期223-231,共9页
The partial charge simulation method is presented to solve the characteristicimpedance of the transmission line of specific cross section with an offset inner conductor.Thismethod has a higher accuracy due to the accu... The partial charge simulation method is presented to solve the characteristicimpedance of the transmission line of specific cross section with an offset inner conductor.Thismethod has a higher accuracy due to the accurate satisfaction of the boundary condition on theouter conductor.The combined method of the Gauss elimination and optimization is used tosolve the equation of charge simulation,and it is an effective method for increasing the accuracyand assuring the convergence.The Green’s functions of five transmission lines(i.e,with circular,elliptic,rectangular,trough and slab conductor)are given. 展开更多
关键词 Microwave TRANsMIssION line OFFsET and sPECIFIC CROss-sECTION TRANsMIssION line Green’s function Partial-charge-simulation Optimization
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ZTE’s CDMA Wireless Subscriber Capacity Exceeds 50 Million Lines
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《ZTE Communications》 2006年第4期70-70,共1页
关键词 CDMA s CDMA Wireless subscriber Capacity Exceeds 50 Million lines ZTE
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On the Existence of Non-Intersecting Straight Lines on the Plane
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作者 Andrew Chubykalo Sergey Artekha 《Journal of Modern Physics》 2018年第5期816-819,共4页
In this brief note, we adduce the logical rationale that if at least one infinite straight line non-intersecting with the given straight line passes through a given point not lying on a given straight line, then it mu... In this brief note, we adduce the logical rationale that if at least one infinite straight line non-intersecting with the given straight line passes through a given point not lying on a given straight line, then it must be unique. 展开更多
关键词 INFINITE straight line Euclid’s FIFTH Postulate Non-Euclidean GEOMETRIEs
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Activation of Sonic Hedgehog Signaling Pathway in S-type Neuroblastoma Cell Lines
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作者 周昱男 戴若连 +4 位作者 毛玲 夏远鹏 姚玉芳 杨雪 胡波 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第3期271-277,共7页
The effects of Sonic hedgehog(Shh) signaling pathway activation on S-type neuroblastoma(NB) cell lines and its role in NB tumorigenesis were investigated.Immunohistochemistry was used to detect the expression of Shh p... The effects of Sonic hedgehog(Shh) signaling pathway activation on S-type neuroblastoma(NB) cell lines and its role in NB tumorigenesis were investigated.Immunohistochemistry was used to detect the expression of Shh pathway components— Patched1(PTCH1) and Gli1 in 40 human primary NB samples.Western blotting and RT-PCR were used to examine the protein expression and mRNA levels of PTCH1 and Gli1 in three kinds of S-type NB cell lines(SK-N-AS,SK-N-SH and SHEP1),respectively.Exogenous Shh was administrated to activate Shh signaling pathway while cyclopamine was used as a selective antagonist of Shh pathway.S-type NB cell lines were treated with different concentrations of Shh or/and cyclopamine for different durations.Cell viability was measured by using MTT method.Apoptosis rate and cell cycle were assayed by flow cytometry.The xenograft experiments were used to evaluate the role of Shh pathway in tumor growth in immunodeficient mice.High-level expression of PTCH1 and Gli1 was detected in both NB samples and S-type NB cell lines.Cyclopamine decreased the survival rate of the three cell lines while Shh increased it,and the inhibition effects of cyclopamine could be partially reversed by shh pre-treatment.Cyclopamine induced the cell apoptosis and the cell cycle arrest in G0/G1 phase,while Shh induced the reverse effects and could partially prevent effects of cyclopamine.Cyclopamine could also inhibit the growth of NB in vivo.Our studies revealed that activation of the Shh pathway is important for survival and proliferation of S-type NB cells in vivo and in vitro through affecting cell apoptosis and cell cycle,suggesting a new therapeutic approach to NB. 展开更多
关键词 s-type neuroblastoma cell lines sonic hedgehog signaling pathway CYCLOPAMINE
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优质籼型光温敏核不育系荃时S的选育与应用
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作者 丁友奇 《园艺与种苗》 CAS 2024年第8期94-95,98,共3页
介绍了荃时S的选育过程、特征特性、配组应用及繁殖技术要点。荃时S是以银312S为母本,与配合力好的优良恢复系YR0822杂交,采用系谱法选育而成的籼型光温敏核不育系,具有育性转换起点温度较低、不育性稳定、异交率高、抗倒伏、米质优等特... 介绍了荃时S的选育过程、特征特性、配组应用及繁殖技术要点。荃时S是以银312S为母本,与配合力好的优良恢复系YR0822杂交,采用系谱法选育而成的籼型光温敏核不育系,具有育性转换起点温度较低、不育性稳定、异交率高、抗倒伏、米质优等特点,2021年通过安徽省农作物品种审定委员会组织的专家技术鉴定。该不育系与恢复系银泰香占配制的籼型两系杂交水稻品种时两优泰香具有中抗稻瘟病、米质达部标优1级、丰产等特点,并获得2022年(第四届)安徽省优质稻品种食味品质籼稻金奖,2022年通过国家农作物品种审定委员会审定。 展开更多
关键词 杂交水稻 光温敏核不育系 荃时s 选育
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大跨度S形舞台升降台设计
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作者 丁守红 张凤宝 《现代制造技术与装备》 2024年第6期28-31,共4页
针对大跨度S形舞台升降台设计中的难点进行分析,优选多组多点钢丝绳卷扬提升方式,采用双驱动系统同步驱动,并阐述多分段刚性传动轴的折线布置方法。结合工程实例提出经济、合理的设计方案,为此类设备的设计提供参考。
关键词 s形升降台 大跨度 钢丝绳卷扬 双驱动 传动轴折线布置
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Comparative Studies on the Changes of Microtubule Distribution and Reorganization During the Meiotic Stages of Development in Normal (IR36) and a Temperature/photoperiod Sensitive Male Sterile Line (Peiai 64S) of Rice ( Oryza sativa ) 被引量:3
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作者 徐是雄 刘向东 +1 位作者 冯九焕 卢永根 《Acta Botanica Sinica》 CSCD 2001年第3期221-226,共6页
Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sen... Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sensitive male sterile line (Peiai 64S) of rice were studied using immunofluorescence confocal microscopy. In IR36, from pre-meiotic interphase to metaphase I, the pattern of microtubule distribution in the meiocytes underwent a series of changes. Some new organizational patterns of microtubules (that have not been described before) were observed during microsporogenesis, including the existence of a broad band of perinuclear microtubules at the diakinesis stage of development. The pattern of microtubule distribution in the meiocytes of the male sterile line, Peiai 64S, was quite different front that seen in IR36. In Peiai 64S, the microtubules showed abnormal patterns of distribution from pre-meiotic interphase to metaphase I. For example the broad band of perinuclear microtubules seen at diakinesis in IR36 was much disorganized and loosened in Peiai 64S. The spindles formed were also very abnormal and different from the normal spindle. The appearance of abnormal microtubule distribution in the early stages of microsporogenesis may contribute to the malformation and ultimate abortion of pollen in Peiai 64S. 展开更多
关键词 Oryza sativa temperature/photoperiod sensitive male sterile rice line microtubules Peiai 64s IR36 microsporocyte meiosis microsporogenesis
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Breeding and Application of Indica PTGMS Line Yan 161S and Its Hybrid Yanliangyou 1618 in Rice
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作者 孙明法 严国红 +12 位作者 唐红生 王爱民 朱国永 何冲霄 任仲玲 刘凯 张桂云 施伟 万林生 孙红芹 倪正斌 单忠德 姚立生 《Agricultural Science & Technology》 CAS 2015年第6期1140-1143,共4页
In 2006, the indica photoperiod- and thermo-sensitive genic male sterile (PTGMS) line Yan 161S was successful y bred by crossing the Guangzhan 63S (♀) and the medium indica breeding material Yan 229 (♂), which... In 2006, the indica photoperiod- and thermo-sensitive genic male sterile (PTGMS) line Yan 161S was successful y bred by crossing the Guangzhan 63S (♀) and the medium indica breeding material Yan 229 (♂), which was bred by the Institute of Agricultural Sciences in Coastal Region of Jiangsu Province, after years' and generations’ selection in different areas. It passed the identification by Jiangsu Provincial Crop Variety Appraisal Committee in 2013. Crossing the Yan 161S with Yanhui 888, a new high-yielding and high-quality two-line hybrid rice combination Yanliangyou 1618 was developed, and it passed the variety identification in 2014. This paper introduced the breeding processes and characteristics of Yan 161S and Yanliangyou 1618 and the cultivation and seed production techniques of Yanliangyou 1618. 展开更多
关键词 盐161s Two-line hybrid rice PTGMs line Yan 161s BREEDING
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Breeding and Application of Indica PTGMS Line Yan 220S in Rice
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作者 孙明法 严国红 +10 位作者 唐红生 王爱民 朱国永 何冲霄 任仲玲 刘凯 张桂云 施伟 赵绍路 孙一标 姚立生 《Agricultural Science & Technology》 CAS 2017年第8期1410-1412,共3页
Yan 220S, which is derived from a natural variant plant discovered among the population of Guangzhan 63S and developed by Jiangsu Agricultural Research Institute for Coastal Regions through pedigree selection over yea... Yan 220S, which is derived from a natural variant plant discovered among the population of Guangzhan 63S and developed by Jiangsu Agricultural Research Institute for Coastal Regions through pedigree selection over years, is an indica photo- and thermo-sensitive genic male sterile (PTGMS) line in rice. In 2013, it was technically identified by Jiangsu Crop Variety Appraisal Committee. Its hybrid Yan-liangyou 2208 (Yan 220S/Yanhui 888), a new two-line hybrid rice combination with high yield and good grain quality, was subsequently developed and released for commercial production by the National Crop Variety Appraisal Committee in 2013. 展开更多
关键词 Hybrid rice PTGMs line Yan 220s BREEDING
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基于Pearson相关系数与广义S变换的低压直流微电网的故障选线方法 被引量:6
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作者 高淑萍 李晓芳 +2 位作者 宋国兵 郑瀚 郭芳宾 《电力系统保护与控制》 EI CSCD 北大核心 2023年第15期120-129,共10页
针对低压直流微电网线路的故障选线方法的研究有限,提出一种基于Pearson相关系数与广义S变换的故障选线方法。首先,介绍了低压直流微电网的一般组成。在此基础上,研究了低压直流微电网的单极故障以及极间故障的故障特征,提出选线方法,... 针对低压直流微电网线路的故障选线方法的研究有限,提出一种基于Pearson相关系数与广义S变换的故障选线方法。首先,介绍了低压直流微电网的一般组成。在此基础上,研究了低压直流微电网的单极故障以及极间故障的故障特征,提出选线方法,对各线路正负极首末端电流差进行Pearson相关系数计算来确定故障线路。然后对所选故障线路正负线路首端的电流量进行广义S变换,计算出其能量和的比值判别故障极性或者极间故障。最后,在PSCAD/EMTDC中搭建出低压直流微电网模型以输出各线路电流数据,并利用Matlab对数据进行仿真。结果表明,所提选线方法直接有效,且耐受过渡电阻的能力较强。 展开更多
关键词 低压直流微电网 广义s变换 Pearson相关系数 单极故障 故障选线
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Comparison of Treatment Efficacy of Different Number of Botulinum Toxin Type A Injection Sites for Crow’s Feet Lines: A Single-Center Retrospective Clinical Study in Vietnam
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作者 Minh Nguyen Quang Mai Le Thi +2 位作者 Hieu Duong Phuc Ha Vu Thai Doanh Le Huu 《International Journal of Dermatology and Venereology》 CSCD 2024年第3期131-136,共6页
Objective:Botulinum toxin type A is frequently used to treat crow’s feet lines.However,the optimal dose and injection sites are still controversial.The objective of this study was to compare the efficacy of different... Objective:Botulinum toxin type A is frequently used to treat crow’s feet lines.However,the optimal dose and injection sites are still controversial.The objective of this study was to compare the efficacy of different botulinum toxin type A injection patterns for the treatment of crow’s feet.Methods:This single-center,retrospective,clinical study was conducted at the National Hospital of Dermatology and Venereology from July 2020 to December 2020.Data on 60 patients with crow’s feet were collected and divided into 2 groups(3-or 4-point intramuscular injection)according to the intramuscular injection technique the patients received.The treatment efficacy was assessed based on the changes in the Crow’s Feet Grading Scale score at 1,4,and 16 weeks after treatment.Repeated measures analysis of variance was used for the assessment of changes in scores over time between the two groups.Results:After treatment,the average Crow’s Feet Grading Scale score was significantly decreased compared with the pretreatment score at all timepoints(1,4,and 16 weeks)in both states(dynamic:For 3-point intramuscular injection technique,1 week:1.90±0.71 vs.2.97±0.56;4 weeks:1.87±0.68 vs.2.97±0.56;16 weeks:2.60±0.67 vs.2.97±0.56.For 4-point intramuscular injection technique,1 week:1.73±0.83 vs.3.03±0.49;4 weeks:1.73±0.74 vs.3.03±0.49;16 weeks:2.57±0.68 vs.3.03±0.49,all P<0.001.and static:For 3-point intramuscular injection technique,1 week:1.20±0.89 vs.2.20±0.85;4 weeks:1.20±0.89 vs.2.20±0.85;16 weeks:1.87±0.97 vs.2.20±0.85;For 4-point intramuscular injection technique,1 week:1.50±0.86 vs.2.30±0.84;4 weeks:1.33±0.84 vs.2.30±0.84;16 weeks:1.87±0.97 vs.2.30±0.84.All P<0.001).The average subjective patient-rated satisfaction scores after treatment were significantly higher in the 4-point injection group than in the 3-point injection group(P=0.028).The adverse events were post-injection bruising in 3 patients and a feeling of eyelid tightness in 3 patients.Conclusion:Botulinum toxin type A injection is an effective treatment for crow’s feet.Adding a fourth injection maintains the same therapeutic effect and does not increase adverse effects.Patients with lower-fan crow’s feet patterns may benefit more from 4-point injection therapy.However,the present findings require confirmation in studies with larger sample sizes,longer follow-up times,and different botulinum toxin type A doses. 展开更多
关键词 botulinum toxin type A crow’s feet lines injection site DOsE
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