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Fengyun Meteorological Satellite Products for Earth System Science Applications 被引量:15
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作者 Di XIAN Peng ZHANG +3 位作者 Ling GAO Ruijing SUN Haizhen ZHANG Xu JIA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第8期1267-1284,共18页
Following the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerica... Following the progress of satellite data assimilation in the 1990s, the combination of meteorological satellites and numerical models has changed the way scientists understand the earth. With the evolution of numerical weather prediction models and earth system models, meteorological satellites will play a more important role in earth sciences in the future. As part of the space-based infrastructure, the Fengyun (FY) meteorological satellites have contributed to earth science sustainability studies through an open data policy and stable data quality since the first launch of the FY-1A satellite in 1988. The capability of earth system monitoring was greatly enhanced after the second-generation polar orbiting FY-3 satellites and geostationary orbiting FY-4 satellites were developed. Meanwhile, the quality of the products generated from the FY-3 and FY-4 satellites is comparable to the well-known MODIS products. FY satellite data has been utilized broadly in weather forecasting, climate and climate change investigations, environmental disaster monitoring, etc. This article reviews the instruments mounted on the FY satellites. Sensor-dependent level 1 products (radiance data) and inversion algorithm-dependent level 2 products (geophysical parameters) are introduced. As an example, some typical geophysical parameters, such as wildfires, lightning, vegetation indices, aerosol products, soil moisture, and precipitation estimation have been demonstrated and validated by in-situ observations and other well-known satellite products. To help users access the FY products, a set of data sharing systems has been developed and operated. The newly developed data sharing system based on cloud technology has been illustrated to improve the efficiency of data delivery. 展开更多
关键词 Fengyun meteorological satellite sensor-dependent level 1 product inversion algorithm-dependent level 2 product product validation
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符合功能安全的Level2层VCU架构设计 被引量:1
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作者 董浩 万继云 刘贵恒 《质量与认证》 2021年第11期61-63,67,共4页
由工信部发布的《智能网联汽车生产企业及产品准入管理指南(试行)》(征求意见稿)中第九条规定:智能网联汽车产品应满足功能安全、功能安全测试等过程保障要求。故而在基于E-Gas三层架构的基础上,根据功能安全软件架构要求,采用基于模型... 由工信部发布的《智能网联汽车生产企业及产品准入管理指南(试行)》(征求意见稿)中第九条规定:智能网联汽车产品应满足功能安全、功能安全测试等过程保障要求。故而在基于E-Gas三层架构的基础上,根据功能安全软件架构要求,采用基于模型开发MBD设计了整车控制器VCU的Level1功能层和Level2监控层软件架构。对Level2监控层的信号校验、过程处理监控和输出监控策略进行设计,设计了探测对应失效的安全机制,以及对应安全状态。最后进行安全分析,并利用静态代码检查工具对模型进行功能安全规范和MAB规范进行检查,通过模型测试工具进行集成测试,结果表明,Level2监控层模型符合需求设计和功能安全要求。 展开更多
关键词 功能安全 整车控制器 软件架构 level2监控层
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RH二级系统加料控制方法的研究与创新
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作者 廖慧 刘丹妹 沈会良 《自动化博览》 2013年第9期114-115,122,共3页
本文提供了一种RH二级控制系统真空料仓的控制方法,采用二级控制软件,将物料控制模式化。通过二级控制软件与一级基础自动化控制系统数据通讯,研发了无废钢仓的物料控制方法,解决了二级系统备料周期长的问题,缩短了冶炼周期,并且在物料... 本文提供了一种RH二级控制系统真空料仓的控制方法,采用二级控制软件,将物料控制模式化。通过二级控制软件与一级基础自动化控制系统数据通讯,研发了无废钢仓的物料控制方法,解决了二级系统备料周期长的问题,缩短了冶炼周期,并且在物料控制的同时实现了对环流、泵级以及氧枪的控制,优化了生产过程,提高了企业的自动化水平。 展开更多
关键词 二级系统 客户端 备料 投料 料仓
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谁偷看了你的底牌
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作者 付涛 范军利 《财经》 2008年第7期69-71,共3页
“Level2和Topview我们都购买了,”一位交易员说,“如果其他机构买了,我们不买,恐怕就会吃亏。”
关键词 上海证券交易所信息网络有限公司 level2行情系统 资讯服务收入 职能定位 证券市场
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限价订单簿的价格发现功能——基于上海证券交易所Level-2行情数据的实证研究
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作者 叶军 《世界经济情况》 2011年第5期75-83,共9页
基于上海证券交易所Level-2行情数据,本文采用Hasbrouck信息份额方法估计了最优买卖报价、最近成交价及第2至第10档次优买卖报价对价格发现的贡献度,尤其关注次优限价订单对资产有效价格的解释能力。研究结果表明:最优限价订单的贡... 基于上海证券交易所Level-2行情数据,本文采用Hasbrouck信息份额方法估计了最优买卖报价、最近成交价及第2至第10档次优买卖报价对价格发现的贡献度,尤其关注次优限价订单对资产有效价格的解释能力。研究结果表明:最优限价订单的贡献度最大,在价格发现中提供了63.82%的信息份额;最近成交价的贡献度为14.76%;次优限价订单有助于价格发现,其贡献度为21.43%;次优限价订单的信息含量随订单主动性的下降而递减;随着交易活跃度的下降,投资者更倾向于提交限价订单,从而导致次优限价订单包含更多信息价值;次优限价订单的信息含量随公司规模和Beta系数的上升而单调下降。 展开更多
关键词 Level—2行情价格发现Hasbrouck信息份额方法
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加热炉自动装出钢过程控制研究 被引量:1
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作者 赵维娜 彭爱辉 《工业控制计算机》 2010年第4期50-51,共2页
加热炉是轧钢工业必须配备的热处理设备,随着工业自动化技术的不断发展,它的自动化程度也在不断得到完善。通过分析首钢京唐2250加热炉过程控制系统的实际应用情况,介绍了关于加热炉过程控制系统的控制时序以及系统的优化。
关键词 过程控制系统 二级 报文 时序 进程
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动态分支预测技术分析与量化研究 被引量:1
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作者 肖泽强 《信息技术》 2011年第3期80-82,共3页
随着现代微处理器的流水线变得越来越深,指令发射宽度越来越大,预测失败所带来的时间代价和空间(功能部件)有效利用率损失也越来越大,预测准确率对流水线的性能的影响也越来越重要。为了量化研究不同动态分支预测技术的准确率,采用计算... 随着现代微处理器的流水线变得越来越深,指令发射宽度越来越大,预测失败所带来的时间代价和空间(功能部件)有效利用率损失也越来越大,预测准确率对流水线的性能的影响也越来越重要。为了量化研究不同动态分支预测技术的准确率,采用计算机体系结构模拟软件Simple Scalar和SPEC 2000 Benchmark,对2bC,GAg,PAg,GAp,PAp,G-share六种动态预测技术的分支方向和分支地址预测准确率进行了性能模拟与测试,最后对模拟结果进行统计分析,得出预测准确率与硬件实现复杂度之间的量化关系,为设计出具有高准确率和低复杂度的动态分支预测器提供了参考。 展开更多
关键词 动态分支预测 BTB 2bC预测 2level预测 BHR PHT SIMPLE SCALAR
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Plasma MMP-2 and MMP-7 levels are elevated first month after surgery and may promote growth of residual metastases 被引量:3
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作者 HMC Shantha Kumara Hiromichi Miyagaki +4 位作者 Sajith A Herath Erica Pettke Xiaohong Yan Vesna Cekic Richard L Whelan 《World Journal of Gastrointestinal Oncology》 SCIE 2021年第8期879-892,共14页
BACKGROUND MMP-2 also known as gelatinase A and MMP-7(matrilysin)are members of the zinc-dependent family of MMPs(Matrix metalloproteinase).MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix;MMP-2... BACKGROUND MMP-2 also known as gelatinase A and MMP-7(matrilysin)are members of the zinc-dependent family of MMPs(Matrix metalloproteinase).MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix;MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage,inflammation,and in stromal cells of metastatic tumors.MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors.Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology.AIM To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology.METHODS Patients enrolled in a plasma bank for whom plasma was available were eligible.Plasma obtained from preoperative(Preop)and postoperative blood samples was used.Only colorectal cancer(CRC)patients who underwent elective minimally invasive cancer resection with preop,post-operative day(POD)1,3 and at least 1 late postop sample(POD 7-34)were included.Late samples were bundled into 7 d blocks(POD 7-13,14-20,etc.)and treated as single time points.Plasma MMP-2 and MMP-7 levels were determined via enzyme-linked immunosorbent assay in duplicate.RESULTS Total 88 minimally invasive CRC resection CRC patients were studied(right colectomy,37%;sigmoid,24%;and LAR/AR 18%).Cancer stages were:1,31%;2,30%;3,34%;and 4,5%.Mean Preop MMP-2 plasma level(ng/mL)was 179.3±40.9(n=88).Elevated mean levels were noted on POD1(214.3±51.2,n=87,P<0.001),POD3(258.0±63.9,n=80,P<0.001),POD7-13(229.9±62.3,n=65,P<0.001),POD 14-20(234.9±47.5,n=25,P<0.001),POD 21-27(237.0±63.5,n=17,P<0.001,)and POD 28-34(255.4±59.7,n=15,P<0.001).Mean Preop MMP-7 level was 3.9±1.9(n=88).No significant differences were noted on POD 1 or 3,however,significantly elevated levels were noted on POD 7-13(5.7±2.5,n=65,P<0.001),POD 14-20(5.9±2.5,n=25,P<0.001),POD 21-27(6.1±3.6,n=17,P=0.002)and on POD 28-34(6.8±3.3,n=15 P<0.001,)vs preop levels.CONCLUSION MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6.The etiology of these changes in unclear,trauma and wound healing likely play a role.These changes may promote residual tumor growth and metastasis. 展开更多
关键词 Effects of surgery Colorectal resection Colorectal cancer Plasma MMP-2 and MMP-7 levels Angiogenesis
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适合广电网络架构的高附加值业务开发
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作者 戴征宇 《广播电视信息》 2012年第7期35-36,共2页
本文分析了广电网络架构特点及适合在其上开发的高附加值业务,并以实时证券行情传输为例,分析说明了其在广电网传输的技术可行性。
关键词 广播电视网有线数字电视 证券行情level2 服务 延迟
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对PostScript Level 2用于颜色再现的评估 被引量:1
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作者 宣柱香 陈虹 《中国印刷》 1997年第5期35-36,51,共3页
本文论述了PostScript Level 2页面描述语言与当前的Level 1相比所具有的优缺点。Level 2的主要优点在于对颜色再现的优势,它包括实现了独立于设备的色彩、数据压缩和解压滤波,更优化的内存管理和改进后的网目调算法。文中同时还说明了... 本文论述了PostScript Level 2页面描述语言与当前的Level 1相比所具有的优缺点。Level 2的主要优点在于对颜色再现的优势,它包括实现了独立于设备的色彩、数据压缩和解压滤波,更优化的内存管理和改进后的网目调算法。文中同时还说明了目前市场上Level 2为什么装备得还很少的几点原因。指出当今市场公认的主要障碍是缺乏工作驱动器,但这个问题不久就能克服。 展开更多
关键词 印刷设备 POSTSCRIPT level2 描述语言 计算机
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TMIS中央实时处理系统的容错设计与实现
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作者 陈镛 《铁路计算机应用》 1997年第3期21-24,共4页
为保证TMIS系统具有很好的容错能力,从硬件、软件、网络等方面都采取了必要的容错措施。本文涉及的只是中央实时处理软件的容错设计与实现,即在中央实时处理软件的设计和开发中,如何采用软件排错、软件容错技术以提高软件的可靠性。
关键词 软件测试 软件排错 软件复查 LEVEL 2测试 3-PARTITION测试 软件容错 实施逻辑
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英国BIM技术在核电工程项目上的应用研究
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作者 严家福 赵栋 《制造业自动化》 CSCD 北大核心 2022年第6期1-3,23,共4页
核电工程项目逐渐规定使用BIM技术为项目节省成本和提高效率,与BIM技术目前在传统建筑工程项目有比较成熟的工程应用不同,核电工程项目在工程管理、施工工艺、平台工具、信息安全等方面都在起步阶段,无法直接套用建筑项目的BIM应用经验... 核电工程项目逐渐规定使用BIM技术为项目节省成本和提高效率,与BIM技术目前在传统建筑工程项目有比较成熟的工程应用不同,核电工程项目在工程管理、施工工艺、平台工具、信息安全等方面都在起步阶段,无法直接套用建筑项目的BIM应用经验,甚至都很难套用BIM的相关标准。通过深入研究英国BIM标准和技术理论体系,结合核电工程项目设计和建造的特点,找到适合核电项目的满足当前BIM Level 2要求的应用解决方案。 展开更多
关键词 BIM Level 2 公共数据环境 核电工程
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DCS二层组态数据优化对降低平台负荷的可行性研究
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作者 万舒 龚蕾 李凯 《电子技术应用》 2021年第S01期323-327,共5页
福清核电1-4号机组采用全厂数字化控制系统(DCS),其中DCS二层系统作为操作员监视和控制机组运行的重要部分,其运行稳定性直接影响核电机组运行的安全性。介绍了DCS二层系统的设备组成、数据通信处理机制。基于二层组态数据优化对降低平... 福清核电1-4号机组采用全厂数字化控制系统(DCS),其中DCS二层系统作为操作员监视和控制机组运行的重要部分,其运行稳定性直接影响核电机组运行的安全性。介绍了DCS二层系统的设备组成、数据通信处理机制。基于二层组态数据优化对降低平台运行负荷的可行性进行了分析,提出了通过优化组态配置参数及智能化清理无用数据来减少单位时间CCT的数据处理量从而降低平台运行负荷的改进方案。创建了DCS一二层组态数据匹配的算法,实现快速定位数据库中的废弃组态。结果表明,优化模拟量扫描时间、最小变化率及清除数据库中的废弃数据能够有效降低二层平台运行负荷,解决在机组繁忙工况出现数据延迟的问题。该改进方法对其他机组降低DCS二层平台运行负荷具有良好的借鉴作用。 展开更多
关键词 DCS二层系统 运行负荷 数据优化
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Is T1-2 Disc Herniation Rare? A Case Report
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作者 Murat Aydin Emrah Akcay Alattin Yurt 《International Journal of Clinical Medicine》 2014年第8期444-446,共3页
Backround: The English literature contains very few reports on disc herniation at upper thoracic levels. This report presents a patient with T1-2 disc herniation who underwent successful surgery. Case Presentation: A ... Backround: The English literature contains very few reports on disc herniation at upper thoracic levels. This report presents a patient with T1-2 disc herniation who underwent successful surgery. Case Presentation: A 47-year-old female presented that the right T1 root was compressed by foraminal disc herniation at the T1-2 level. Conclusion: The anterior approach is an easy and appropriate method to treat central and foraminal disc herniation of the thoracic spine. 展开更多
关键词 Disc Herniation Thoracic Spine T1-2 Level SURGERY
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用比湿数据及独立成分分析研究ENSO在对流层上层的响应
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作者 李力 陈志平 《北京测绘》 2024年第3期305-311,共7页
基于2006—2016年气象、电离层与气候卫星观测系统(COSMIC)提供的level 2‘wetPrf’比湿数据集,首次提出了独立成分分析(ICA)联合低通滤波的方法提取对流层上层的厄尔尼诺-南方涛动(ENSO)信号。结合现有的气象学研究与传统方法主成分分... 基于2006—2016年气象、电离层与气候卫星观测系统(COSMIC)提供的level 2‘wetPrf’比湿数据集,首次提出了独立成分分析(ICA)联合低通滤波的方法提取对流层上层的厄尔尼诺-南方涛动(ENSO)信号。结合现有的气象学研究与传统方法主成分分析(PCA)的结果,分析了ENSO信号在对流层上层的响应。结果表明:ICA提取的ENSO信号具有更高的可靠性、有效性和可解释性,且得到了现有气象研究很好的支撑。该方法很好地分离出具有不同区域特征的源信号,凸显了这种基于信息理论的方法在ENSO信号提取方面的潜力。 展开更多
关键词 厄尔尼诺-南方涛动 气象、电离层与气候卫星观测系统 level 2‘wetPrf’比湿数据 独立成分分析
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Subjective assessment for an advanced driver assistance system:a case study in China
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作者 Di Ao Jialin Li 《Journal of Intelligent and Connected Vehicles》 2022年第2期112-122,共11页
Purpose–This study aims to propose a novel subjective assessment(SA)method for level 2 or level 21 advanced driver assistance system(ADAS)with a customized case study in China.Design/methodology/approach–The propose... Purpose–This study aims to propose a novel subjective assessment(SA)method for level 2 or level 21 advanced driver assistance system(ADAS)with a customized case study in China.Design/methodology/approach–The proposed SA method contains six dimensions,including perception,driveability and stability,riding comfort,human–machine interaction,driver workload and trustworthiness and exceptional operating case,respectively.And each dimension subordinates several subsections,which describe the corresponding details under this dimension.Findings–Based on the proposed SA,a case study in China is conducted.Six drivers with different driving experiences are invited to give their subjective ratings for each subsection according to a predefined rating standard.The rating results show that the ADAS from Tesla outperforms the upcoming electric vehicle in most cases.Originality/value–The proposed SA method is beneficial for the original equipment manufacturers developing related technologies in the future. 展开更多
关键词 Level 2 or 21 Advanced driver assistance system Subjective assessment method Six dimensions Case study
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限价指令簿的价格发现功能 被引量:4
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作者 刘红忠 叶军 《复旦学报(社会科学版)》 CSSCI 北大核心 2012年第2期35-42,共8页
基于上海证券交易所Level—2行情数据,本文运用Hasbrouck信息份额方法分别估计最近成交价、限价指令簿中最优买卖报价及第2—10档次买卖报价在价格发现中的贡献度,以考察限价指令簿的价格发现功能,尤其关注次优限价指令对价格发现的影... 基于上海证券交易所Level—2行情数据,本文运用Hasbrouck信息份额方法分别估计最近成交价、限价指令簿中最优买卖报价及第2—10档次买卖报价在价格发现中的贡献度,以考察限价指令簿的价格发现功能,尤其关注次优限价指令对价格发现的影响。我们认为,次优限价指令有助于价格发现,其贡献度为21.43%,而且其贡献度随指令主动性的下降而递减;最优限价指令的贡献度最大,为63.82%;最近成交价的贡献度最小,为14.76%;另外,本文还考察了个股横截面特征是否影响次优限价指令对价格发现的贡献度。实证结果表明:随着个股交易活跃度的下降,投资者更倾向于提交限价指令,从而导致次优限价指令对价格发现的贡献度增加;同时,其贡献度随公司规模和Beta系数的上升而单调下降。 展开更多
关键词 限价指令簿 Level—2行情 价格发现 Hasbrouck信息份额方法
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Effects of elevated CO_2 levels on root morphological traits and Cd uptakes of two Lolium species under Cd stress 被引量:4
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作者 Yan JIA Shi-rong TANG +4 位作者 Xue-hai JU Li-na SHU Shu-xing TU Ren-wei FENG Lorenzino GIUSTI 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第4期313-325,共13页
This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two C... This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0,4,and 16 mg/L) under hydroponic conditions.The results show that elevated levels of CO2 increased shoot biomass more,compared to root biomass,but decreased Cd concentrations in all plant tissues.Cd exposure caused toxicity to both Lolium species,as shown by the restrictions of the root morphological parameters including root length,surface area,volume,and tip numbers.These parameters were significantly higher under elevated levels of CO2 than under ambient CO2,especially for the number of fine roots.The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress,suggesting an ameliorated Cd stress under elevated levels of CO2.The total Cd uptake per pot,calculated on the basis of biomass,was significantly greater under elevated levels of CO2 than under ambient CO2.Ameliorated Cd toxicity,decreased Cd concentration,and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation. 展开更多
关键词 Elevated CO2 levels Lolium multiflorum Lam. Lolium perenne L. Root morphology Cd uptake Cd stress
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Transcriptome responses to elevated CO2 level and Wolbachia-lniecWon stress in Hylyphantes graminicola (Araneae: Linyphiidae)
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作者 Qi-Chen Su Xia Wang +3 位作者 Chan Deng Yue-Li Yun Yao Zhao Yu Peng 《Insect Science》 SCIE CAS CSCD 2020年第5期908-920,共13页
Hybyphantes graminicola is a resident spider species found in maize and cotton fields and is an important biological control agent of various pests.Previous studies have demonstrated that stress from elevated CO2 and ... Hybyphantes graminicola is a resident spider species found in maize and cotton fields and is an important biological control agent of various pests.Previous studies have demonstrated that stress from elevated CO2 and Wolbachia infection can strongly affect spider species.Thus,based on CO2 levels(400 ppm,current atmospheric CO2 concentration and 800 ppm,high CO2 concentration)and Wolbachia status(Wolbachia-infected,W^+and Wolbachia-uninfected,W^-),we divided H.graminicola individuals into four treatment groups:W^-400 ppm,W^-800 ppm,W^+400 ppm,and W^+800 ppm.To investigate the effects of elevated CO2 levels(W^-400 vs W^-800),Wolbachia infection(W^-400 vs W^+400),and the interactions between these two factors(W^-400 Vs W^+800),high-throughput transcriptome sequencing was employed to characterize the de novo transcriptome of the spiders and identify stress-related differentially expressed genes(DEGs).De novo assembly of complementary DNA sequences generated 86688 unigenes,23938 of which were annotated in public databases.A total of 84,21,and 157 DEGs were found among W^-400vs W^-800,W^-400 vs W^+400,and W^-400vs W^+800,respectively.Functional enrichment analysis revealed that metabolic processes,signaling,and catalytic activity were significantly affected by elevated CO2 levels and Wolbachia infection.Our findings suggest that the impact of elevated CO2 levels and Wolbachia infection on the H.graminicola transcriptome was,to a large extent,on genes involved in metabolic processes.This study is the first description of transcriptome changes in response to elevated CO2 levels and WoIbachia infection in spiders. 展开更多
关键词 CO2 level high-throughput Hybyphantes graminicola RT-QPCR transcrip-tome Wolbachia infection
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欧洲列车控制系统在英国东海岸铁路的应用
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作者 李娇娇(译) 张建平(校) 《国外铁道机车与动车》 2021年第3期3-8,13,共7页
为扩展运输业务,英国铁路网公司以更新铁路信号系统及机车车辆为契机,将在英国东海岸干线上推行ETCS Level 2列车控制和交通管理系统。介绍了项目的实施规划及ETCS的应用前景。
关键词 英国铁路网公司 ETCS Level 2 ECDP
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