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TMS320C6678多核DSP的核间通信方法 被引量:27
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作者 吴灏 肖吉阳 +1 位作者 范红旗 付强 《电子技术应用》 北大核心 2012年第9期11-13,共3页
嵌入式应用中采用多处理系统所面临的主要难题是多处理器内核之间的通信。对Key-Stone架构TMS320C6678处理器的多核间通信机制进行研究,利用处理器间中断和核间通信寄存器,设计并实现了多核之间的通信。从系统的角度出发,设计与仿真了... 嵌入式应用中采用多处理系统所面临的主要难题是多处理器内核之间的通信。对Key-Stone架构TMS320C6678处理器的多核间通信机制进行研究,利用处理器间中断和核间通信寄存器,设计并实现了多核之间的通信。从系统的角度出发,设计与仿真了两种多核通信拓扑结构,并分析对比了性能。对设计多核DSP处理器的核间通信有一定的指导价值。 展开更多
关键词 TMS320C6678 keystone 处理器间中断 多核通信
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冬季竞技体育可持续发展探析 被引量:22
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作者 刘福军 《冰雪运动》 2008年第1期59-62,共4页
为保证我国冬季竞技体育的可持续发展,采用文献资料、逻辑分析和调研等方法,对"十一五"期间我国冬季竞技体育的发展战略进行了初步研究。重点分析了我国冬季竞技体育的现状和差距,可持续发展的战略目标和战略重点,提出了继续... 为保证我国冬季竞技体育的可持续发展,采用文献资料、逻辑分析和调研等方法,对"十一五"期间我国冬季竞技体育的发展战略进行了初步研究。重点分析了我国冬季竞技体育的现状和差距,可持续发展的战略目标和战略重点,提出了继续深化"举国体制",实施和推进"北冰南展";认真研究、论证合理的项目布局,巩固并扩大优势;重视和加强高水平后备人才培养;加强国际交流与合作;进一步充分发挥科学技术的作用等战略对策。 展开更多
关键词 冬季项目 竞技体育 目标 重点 对策
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Functional-trait ecology of the plateau pika Ochotona curzoniae in the Qinghai-Tibetan Plateau ecosystem 被引量:18
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作者 Andrew T.SMITH BADINGQIUYING +1 位作者 Maxwell C.WILSON Brigitte W.HOGAN 《Integrative Zoology》 SCIE CSCD 2019年第1期87-103,共17页
Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation planning.The functionaltrait ecology o... Understanding a species’functional traits allows for a directed and productive perspective on the role a species plays in nature,and thus its relative importance to conservation planning.The functionaltrait ecology of the plateau pika Ochotona curzoniae is examined to better understand the resilience and sustainability of the high alpine grasslands of the Qinghai-Tibetan Plateau(QTP).The key functional traits of plateau pikas are their abundance and behavior of digging extensive burrow systems.Plateau pikas have been poisoned over a significant part of their original geographic distribution across the QTP,allowing comparison of ecological communities with and without pikas.Nearly all mammalian and avian carnivores,most of which are obligate predators on pikas,have been lost in regions where pikas have been poisoned.Most endemic birds on the QTP nest in pika burrows;when pikas are poisoned,burrows collapse,and these birds are greatly reduced in number.Due to the biopedturbation resulting from their burrows,regional plant species richness is higher in areas with pikas than without.The presence of pika burrows allows higher rates of infiltration during heavy monsoon rains compared to poisoned areas,possibly mitigating runoff and the potential for serious downslope erosion and flooding.Thus,the functional traits of plateau pikas enhance native biodiversity and other important ecosystem functions;these traits are irreplaceable.As plateau pikas are not natural colonizers,active reintroduction programs are needed to restore pikas to areas from which they have been poisoned to restore the important functional ecological traits of pikas. 展开更多
关键词 ecosystem engineer functional-trait ecology keystone species Ochotona curzoniae RE-INTRODUCTION
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基于Ceph对象存储集群的高可用设计与实现 被引量:15
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作者 杨飞 朱志祥 梁小江 《微电子学与计算机》 CSCD 北大核心 2016年第1期60-64,共5页
为了实现一种基于ceph对象存储集群的高可用设计方案,先搭建ceph集群生态系统,然后设计和部署ceph对象存储集群,实现多对象网关发布对象存储服务.通过keystone统一认证中心保证多区域的用户访问的安全性,最后整合haproxy和keepalived,... 为了实现一种基于ceph对象存储集群的高可用设计方案,先搭建ceph集群生态系统,然后设计和部署ceph对象存储集群,实现多对象网关发布对象存储服务.通过keystone统一认证中心保证多区域的用户访问的安全性,最后整合haproxy和keepalived,设计和实现基于ceph对象存储集群的高可用设计方案.在相同实验环境下,首先测试ceph存储集群健康状况,保证整个ceph存储集群正常运行,最后通过大量的网络压力测试和分析,证明本系统能实现ceph对象存储集群的高可用性. 展开更多
关键词 ceph 高可用性 keystone 对象存储 haproxy
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Keystone design perforator island flap in facial defect reconstruction 被引量:7
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作者 Soo Yeon Lim Chi Sun Yoon +1 位作者 Hyun Gun Lee Kyu Nam Kim 《World Journal of Clinical Cases》 SCIE 2020年第10期1832-1847,共16页
Facial defect coverage is a common subject in the field of reconstructive surgery.There are many methods for facial defect reconstruction,and reconstructive surgeons should choose the most appropriate method on a case... Facial defect coverage is a common subject in the field of reconstructive surgery.There are many methods for facial defect reconstruction,and reconstructive surgeons should choose the most appropriate method on a case-by-case basis to achieve both functional and aesthetic improvement.Among various options for facial reconstruction,the local flap technique is considered the best reconstructive modality to provide good tissue matches of color and texture,which is consistent with the ideal goal of reconstruction(replacement of like-with-like).Keystone design perforator island flap(KDPIF),devised by Behan in 2003,has been applied to various fields of reconstructive surgery in the past decade due to its design simplicity,robust vascular supply,and reproducibility.Several studies have reported KDPIF reconstruction of facial defects,such as large parotid defects,small-to-moderate nasal defects,and eyelid defects.However,KDPIF has been used relatively less in facial defects than in other body regions,such as the trunk and extremities.The purpose of this review is to provide an organized overview of facial KDPIF reconstruction including the classification of KDPIF,modifications,physiology,mechanism of flap movement,consideration of facial relaxed skin tension lines and aesthetics,surgical techniques,clinical applications,and precautions for successful execution of KDPIF reconstruction. 展开更多
关键词 keystone design perforator island flap Reconstructive surgery Facial defects AESTHETICS Plastic surgery Flap surgery
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The Concept, Connotation and Significance of Cultural Keystone Species in Agricultural Heritage Systems 被引量:7
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作者 MIN Qingwen YANG Xiao DING Lubin 《Journal of Resources and Ecology》 CSCD 2022年第1期51-60,共10页
As a new type of heritage, Agricultural Heritage Systems(AHS), represented by Globally Important Agricultural Heritage Systems(GIAHS) designated by Food and Agriculture Organization of the United Nations(FAO)and Natio... As a new type of heritage, Agricultural Heritage Systems(AHS), represented by Globally Important Agricultural Heritage Systems(GIAHS) designated by Food and Agriculture Organization of the United Nations(FAO)and Nationally Important Agricultural Heritage Systems(NIAHS) designated by some countries’ Ministry of Agriculture, are typical Social-Ecological Systems(SES), which usually are rich in biodiversity, traditional knowledge,resource utilization technology and outstanding cultural landscapes. Cultural Keystone Species(CKS) are defined as the culturally salient species that shape the cultural identity of a people in a major way. CKS can be used as a prominent tool for the synergistic conservation of SES biology and culture, and to promote the overall enhancement of system functions. This paper summarizes a review of the definition of the CKS and its application in SES conservation. According to the characteristics and protection needs of AHS, this paper defined the CKS in AHS as:“Composites of biological resources and cultural practices, which have a significant impact on the stability of local society and culture systems, contribute to the achievement of AHS’ conservation goals.” Based on this definition,we analyzed the significance of the identification of CKS in AHS. First of all, CKS help to quickly identify the key elements of AHS. Secondly, CKS can promote community participation in the conservation and development of AHS. In addition, the identification of CKS has a significant role in food and livelihood security, biodiversity conservation, traditional knowledge and technology transmission, social organization maintenance, and cultural landscape maintenance in AHS, which helps to achieve the conservation goals of GIAHS and/or NIAHS. 展开更多
关键词 Agricultural Heritage Systems(AHS) Globally Important Agricultural Heritage Systems(GIAHS) Nationally Important Agricultural Heritage Systems(NIAHS) Cultural keystone Species(CKS) biocultural diversity Social-Ecological Systems(SES)
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Openstack云平台自适应认证系统负载均衡策略研究 被引量:4
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作者 林韧昊 朱智强 +1 位作者 孙磊 胡翠云 《计算机应用与软件》 北大核心 2019年第9期302-309,共8页
Openstack作为开源云平台的行业标准,在身份认证方面主要通过Keystone组件来实现。Keystone作为Openstack认证授权的中枢组件,极易成为性能上的瓶颈,负载过高时会导致云平台无法正常工作。针对Openstack认证系统的效率及能耗问题,提出... Openstack作为开源云平台的行业标准,在身份认证方面主要通过Keystone组件来实现。Keystone作为Openstack认证授权的中枢组件,极易成为性能上的瓶颈,负载过高时会导致云平台无法正常工作。针对Openstack认证系统的效率及能耗问题,提出一种自适应Openstack认证系统负载均衡策略。该策略设计自适应管理框架及自适应策略触发阈值,通过改进朴素贝叶斯算法对节点负载状况进行分类;通过信息熵算法确定各特征值指标的权重,从任务的分发和迁移两个方面对资源进行合理的调度,从而实现负载均衡。通过云仿真平台Cloudsim来验证策略的可行性和有效性,实验结果表明该策略在任务量较大时能使得负载分布更加均衡。 展开更多
关键词 云计算 OPENSTACK keystone 负载均衡 自适应机制 朴素贝叶斯分类算法 信息熵
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F/M对活性污泥微生物生态网络的影响 被引量:6
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作者 张冰 孙晨翔 文湘华 《环境科学》 EI CAS CSCD 北大核心 2022年第3期1529-1534,共6页
为深入理解有机负荷率(F/M)对活性污泥(AS)微生物群落的影响,以F/M(以BOD/MLVSS计,下同)设计建议范围0.2~0.5 kg·(kg·d)^(-1)为依据,将采集的AS样品分为3组,运用基于随机矩阵理论(RMT)的网络分析方法,解析了不同F/M条件下的A... 为深入理解有机负荷率(F/M)对活性污泥(AS)微生物群落的影响,以F/M(以BOD/MLVSS计,下同)设计建议范围0.2~0.5 kg·(kg·d)^(-1)为依据,将采集的AS样品分为3组,运用基于随机矩阵理论(RMT)的网络分析方法,解析了不同F/M条件下的AS微生物生态网络拓扑性质及结构特征.结果表明,较低的F/M能够显著降低AS微生物群落的多样性和均匀度,但较高的F/M未对群落多样性和均匀度产生显著影响,表明多样性指标对高F/M不敏感.不同F/M条件下微生物生态网络均具有无标度、小世界和模块化的特征,但F/M较高或较低均会降低网络的规模及复杂度.当F/M在0.2~0.5 kg·(kg·d)^(-1)范围内,生态网络具有最多的总节点数、最大的平均聚集系数以及最小的平均路径距离;此时的网络规模最大,网络复杂度最高,AS群落的结构和功能也因此最为稳定.不同F/M条件下AS微生物间的正负相互作用关系也存在差异:其中F/M较低时,网络中节点的正连接比例为71.1%;当F/M在0.2~0.5 kg·(kg·d)^(-1)时,微生物间的正相关关系最多,为76.8%;当F/M超过0.5 kg·(kg·d)^(-1)时,正相关关系降至60.0%.此外,F/M在0.2~0.5 kg·(kg·d)^(-1)时网络识别出了24个关键物种,而F/M低于0.2 kg·(kg·d)^(-1)和高于0.5 kg·(kg·d)^(-1)时,网络仅识别出4个和7个关键物种.上述性质均表明F/M在0.2~0.5 kg·(kg·d)^(-1)范围内,AS微生物可能会更高效地进行物质传输和利用,同时抵御环境扰动的能力也更强,群落稳定性更高. 展开更多
关键词 活性污泥(AS) 微生物群落 有机负荷率(F/M) 生态网络 关键物种
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Green manuring relocates microbiomes in driving the soil functionality of nitrogen cycling to obtain preferable grain yields in thirty years 被引量:2
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作者 Guopeng Zhou Kunkun Fan +8 位作者 Songjuan Gao Danna Chang Guilong Li Ting Liang Hai Liang Shun Li Jiudong Zhang Zongxian Che Weidong Cao 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第3期596-610,共15页
Fertilizers are widely used to produce more food, inevitably altering the diversity and composition of soil organisms. The role of soil biodiversity in controlling multiple ecosystem services remains unclear, especial... Fertilizers are widely used to produce more food, inevitably altering the diversity and composition of soil organisms. The role of soil biodiversity in controlling multiple ecosystem services remains unclear, especially after decades of fertilization. Here, we assess the contribution of the soil functionalities of carbon(C), nitrogen(N), and phosphorus(P) cycling to crop production and explore how soil organisms control these functionalities in a 33-year field fertilization experiment. The long-term application of green manure or cow manure produced wheat yields equivalent to those obtained with chemical N, with the former providing higher soil functions and allowing the functionality of N cycling(especially soil N mineralization and biological N fixation) to control wheat production. The keystone phylotypes within the global network rather than the overall microbial community dominated the soil multifunctionality and functionality of C,N, and P cycling across the soil profile(0–100 cm). We further confirmed that these keystone phylotypes consisted of many metabolic pathways of nutrient cycling and essential microbes involved in organic C mineralization, N_(2)O release, and biological N fixation. The chemical N, green manure, and cow manure resulted in the highest abundances of amoB, nifH, and GH48 genes and Nitrosomonadaceae,Azospirillaceae, and Sphingomonadaceae within the keystone phylotypes, and these microbes were significantly and positively correlated with N_(2)O release, N fixation, and organic C mineralization, respectively. Moreover, our results demonstrated that organic fertilization increased the effects of the network size and keystone phylotypes on the subsoil functions by facilitating the migration of soil microorganisms across the soil profiles and green manure with the highest migration rates. This study highlights the importance of the functionality of N cycling in controlling crop production and keystone phylotypes in regulating soil functions, and provides selectable fertilization strategies 展开更多
关键词 soil biodiversity soil multifunctionality element cycling keystone phylotypes
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Research on keystone formatting based on non-baseband interpolation 被引量:3
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作者 Yufei Cao Xiaoguang Qu Peikang Huang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第4期562-565,共4页
When there is Doppler ambiguity number mutation,keystone formatting is no longer valid because of integration performance deterioration and false velocity estimation.A novel keystone formatting method based on non-bas... When there is Doppler ambiguity number mutation,keystone formatting is no longer valid because of integration performance deterioration and false velocity estimation.A novel keystone formatting method based on non-baseband interpolation is presented.It has a different half blind velocity range comparing with normal keystone formatting.Furthermore,there is non-superposition between half-blind-velocity-range of keystone formatting based on baseband and that of non-baseband interpolation.So a synthesizing keystone formatting is proposed to avoid the half-blind-velocity effect.Simulation results of the proposed method show that integration deterioration and velocity estimation falsity can be eliminated effectively. 展开更多
关键词 keystone formatting half-blind-velocity coherent integration velocity estimation.
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OpenStack Keystone认证机制研究 被引量:3
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作者 尹誉衡 《计算机技术与发展》 2021年第2期122-126,共5页
随着云计算技术在政治、经济、科研等领域的广泛应用,对云计算平台的安全要求也越来越高。OpenStack是一个大型开源云计算平台,被广泛应用于私有云和公有云平台的搭建中,其身份认证机制由Keystone组件基于用户名和密码提供,且在传输过... 随着云计算技术在政治、经济、科研等领域的广泛应用,对云计算平台的安全要求也越来越高。OpenStack是一个大型开源云计算平台,被广泛应用于私有云和公有云平台的搭建中,其身份认证机制由Keystone组件基于用户名和密码提供,且在传输过程中以明文传输,容易受到中间人攻击,导致信息被窃取,无法适用于安全要求较高的场景。为了提高Keystone认证机制的安全性,对Keystone的两种认证机制进行了详细分析,指明其中存在的明文传输、易遭受重放攻击等安全问题,针对这些安全问题,提出一种对Keystone认证机制进行改进的方案。该方案结合非对称加密的方式对传输数据进行加密,加入了时间戳验证机制,有效地降低了数据在传输过程中被窃听、被篡改的风险。通过使用Wireshark抓包设置对比实验,证明了该方案的有效性。经分析,该方案降低了Keystone明文传输数据的风险,增强了Keystone传输数据的安全性。 展开更多
关键词 云计算 keystone 安全问题 认证机制 加密传输
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An extended processing scheme for coherent integration and parameter estimation based on matched filtering in passive radar 被引量:3
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作者 Xin GUAN Li-hua ZHONG +1 位作者 Dong-hui HU Chi-biao DING 《Journal of Zhejiang University-Science C(Computers and Electronics)》 SCIE EI 2014年第11期1071-1085,共15页
In passive radars, coherent integration is an essential method to achieve processing gain for target detection. The cross ambiguity function(CAF) and the method based on matched filtering are the most common approache... In passive radars, coherent integration is an essential method to achieve processing gain for target detection. The cross ambiguity function(CAF) and the method based on matched filtering are the most common approaches. The method based on matched filtering is an approximation to CAF and the procedure is:(1) divide the signal into snapshots;(2) perform matched filtering on each snapshot;(3) perform fast Fourier transform(FFT) across the snapshots. The matched filtering method is computationally affordable and can offer savings of an order of 1000 times in execution speed over that of CAF. However, matched filtering suffers from severe energy loss for high speed targets. In this paper we concentrate mainly on the matched filtering method and we use keystone transform to rectify range migration. Several factors affecting the performance of coherent integration are discussed based on the matched filtering method and keystone transform. Modified methods are introduced to improve the performance by analyzing the impacts of mismatching, precision of the keystone transform, and discretization. The modified discrete chirp Fourier transform(MDCFT) is adopted to rectify the Doppler expansion in a multi-target scenario. A novel velocity estimation method is proposed, and an extended processing scheme presented. Simulations show that the proposed algorithms improve the performance of matched filtering for high speed targets. 展开更多
关键词 keystone transform Matched filtering MDCFT Mismatching Passive radar Velocity estimation
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高光谱成像仪中曲面棱镜的装调公差研究 被引量:5
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作者 蔡东浩 李雅灿 +3 位作者 魏立冬 冯蕾 周锦松 景娟娟 《光学学报》 EI CAS CSCD 北大核心 2021年第6期54-62,共9页
基于曲面棱镜的光谱成像技术是近几年该领域研究的热点,但曲面棱镜前后球面的非共轴特性使得曲面棱镜的装调难度远大于传统共轴光学系统。装调误差是影响成像系统最终成像质量的重要因素,目前曲面棱镜高光谱成像仪的公差分配方法大多以... 基于曲面棱镜的光谱成像技术是近几年该领域研究的热点,但曲面棱镜前后球面的非共轴特性使得曲面棱镜的装调难度远大于传统共轴光学系统。装调误差是影响成像系统最终成像质量的重要因素,目前曲面棱镜高光谱成像仪的公差分配方法大多以系统调制传递函数(MTF)为评价指标,未考虑装调误差对谱线弯曲、色畸变的影响。利用几何光学方法研究了曲面棱镜谱线弯曲、色畸变的产生机理,构建了曲面棱镜光谱仪谱线弯曲、色畸变与曲面棱镜装调误差关系的数学模型,分析了曲面棱镜装调误差对高光谱成像仪光谱畸变的影响。通过几何光线追迹,对曲面棱镜装调误差的分析结果进行了验证。结果表明,谱线弯曲、色畸变和MTF对曲面棱镜装调误差的敏感程度存在显著差异。为了保证曲面棱镜装调误差引起的系统MTF下降容限在设计值的10%以内,进行了二次公差分配以得到最终公差分配结果,其中公差极限值最小的单项装调公差为X轴方向的倾斜误差,为实际系统的装调提供了参考。 展开更多
关键词 几何光学 成像光谱仪 曲面棱镜 谱线弯曲 色畸变 光学装调
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双核DSP-TMS320C6657的核间通信方法 被引量:2
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作者 张洪坤 金立左 《工业控制计算机》 2017年第2期21-22,25,共3页
多核通信是嵌入式多核系统应用中极为重要的问题和难题。TMS320C6657是一款双核KeyStone架构的DSP,它提供中断的核间通信方式并为此提供相应的硬件寄存器。通过对这种通信方法的研究,分析比较了其与其他通信手段的区别,详细介绍了中断... 多核通信是嵌入式多核系统应用中极为重要的问题和难题。TMS320C6657是一款双核KeyStone架构的DSP,它提供中断的核间通信方式并为此提供相应的硬件寄存器。通过对这种通信方法的研究,分析比较了其与其他通信手段的区别,详细介绍了中断通信方式的机制,并对此方法进行数据测试。结果显示,中断核间通信方法简单方便、灵活高效、通信稳定,是一种有效方法的多核通信方法。 展开更多
关键词 双核 TMS320C6657 核间通信 IPC 中断 keystone
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基于Openstack Swift的高可用存储方案研究与实现 被引量:2
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作者 张晓莉 文成玉 原子桢 《成都信息工程大学学报》 2019年第1期44-48,共5页
为提高Openstack Swift集群的高可用性,基于Openstack云计算平台,提出一种通用地址冗余协议CARP(common access redundancy protocol)+HAProxy+Swift对象存储相结合的高可用存储解决方案,并针对TempAuth不适合生产环境下集群部署的缺陷... 为提高Openstack Swift集群的高可用性,基于Openstack云计算平台,提出一种通用地址冗余协议CARP(common access redundancy protocol)+HAProxy+Swift对象存储相结合的高可用存储解决方案,并针对TempAuth不适合生产环境下集群部署的缺陷,提出将Swift集群与Openstack Keystone服务相整合的方法。方案将通用地址冗余协议和负载均衡技术有效地融合。经过实验测试可得,改进的集群框架,在保证Swift集群数据安全性的同时,减轻了Swift代理节点的负载压力,增强了整体处理请求能力,提高了集群的高可用性。实验证明,方案具有可行性。 展开更多
关键词 OPENSTACK SWIFT HAProxy CARP keystone 负载均衡
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The structure of mixed-species bird flocks,and their response to anthropogenic disturbance,with special reference to East Asia 被引量:2
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作者 Eben Goodale Ping Ding +4 位作者 Xiaohu Liu Ari Martínez Xingfeng Si Mitch Walters Scott K.Robinson 《Chinese Birds》 CSCD 2015年第3期121-131,共11页
Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology per... Mixed-species flocks of birds are distributed world-wide and can be especially dominant in temperate forests during the non-breeding season and in tropical rainforests year-round.We review from a community ecology perspective what is known about the structure and organization of flocks,emphasizing that flocking species tend to be those particularly vulnerable to predation,and flocks tend to be led by species that are able to act as sources of information about predators for other species.Studies on how flocks respond to fragmentation and land-use intensification continue to accumulate,but the question of whether the flock phenomenon makes species more vulnerable to anthropogenic change remains unclear.We review the literature on flocks in East Asia and demonstrate there is a good foundation of knowledge on which to build.We then outline potentially fruitful future directions,focusing on studies that can investigate how dependent species are on each other in flocks,and how such interdependencies might affect avian habitat selection in the different types of human-modified environments of this region. 展开更多
关键词 Biodiversity crisis Biological networks Community assembly Competition INTERSPECIFIC communication keystone species MUTUALISM Pr
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W波段ISAR包络对齐方法研究 被引量:2
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作者 魏一搏 王辉 《国外电子测量技术》 2015年第9期43-47,56,共6页
在ISAR成像处理中,目标整体在距离方向的位移会使散射点的回波无法落在相同的距离单元内,造成成像结果的散焦,因此采用包络对齐的方法对该位移进行补偿。然而在W波段的ISAR包络对齐处理过程中,较高的分辨率会使回波包络在成像时间内发... 在ISAR成像处理中,目标整体在距离方向的位移会使散射点的回波无法落在相同的距离单元内,造成成像结果的散焦,因此采用包络对齐的方法对该位移进行补偿。然而在W波段的ISAR包络对齐处理过程中,较高的分辨率会使回波包络在成像时间内发生变化,导致传统方法产生对齐误差。针对该问题,提出了一种使用Keystone变换进行包络规整的方法来提高包络对齐的准确度。在Keystone变换之前,使用了目标重心跟踪及补偿的方法来实现回波信号的相干化。实验结果表明,通过包络规整处理,成像结果的极值点强度,图像熵以及图像对比度都得到了较大的提升。 展开更多
关键词 W波段 ISAR 包络对齐 keystone 相干处理
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Organic-inorganic fertilization promotes paddy soil macroaggregate organic carbon accumulation associated with key bacterial populations in subtropical China
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作者 Jinhua ZHAO Lin CHEN +5 位作者 Guixiang ZHOU Fang LI Jiabao ZHANG Congzhi ZHANG Donghao MA Biao FENG 《Pedosphere》 SCIE CAS CSCD 2024年第5期941-950,共10页
Macroaggregate organic carbon(Macro-OC)accumulation in paddy soils is of great significance in promoting multiple agroecosystem services.However,the effects of different fertilization practices on Macro-OC accumulatio... Macroaggregate organic carbon(Macro-OC)accumulation in paddy soils is of great significance in promoting multiple agroecosystem services.However,the effects of different fertilization practices on Macro-OC accumulation in paddy soils at the regional scale have not been comprehensively investigated.Here,we conducted long-term fertilization field experiments at four sites,Taoyuan,Wangcheng,Jinxian,and Suzhou,in the subtropical area of China to reveal the effects of inorganic and organic-inorganic(OIF)fertilization on Macro-OC accumulation and its relationships with important microbial traits(the abundance ratio of GH48:cbhI genes and the richness of keystone bacterial taxa)in paddy soils.The results showed that long-term fertilization(particularly OIF)significantly increased the content of Macro-OC,which mainly consisted of particulate organic carbon(C).Organic-inorganic fertilization decreased the percentage of O-alkyl C but increased the percentages of alkyl,aromatic,and phenolic C.Organic-inorganic fertilization promoted the abundance of the bacterial cellulose-degrading gene GH48 retrieved from macroaggregates.The orders Anaerolineales,Bacillales,and Clostridiales were identified as keystone bacterial taxa in macroaggregates and were significantly correlated with the physical fraction and chemical structure of Macro-OC.Structural equation modeling revealed that fertilization-induced changes in soil pH and C:N ratio affected the richness of Anaerolineales,Bacillales,and Clostridiales,which was strongly associated with the increase of percentages of aromatic and phenolic C and further facilitated Macro-OC accumulation.Together,these results suggested that OIF promoted Macro-OC accumulation associated with key bacterial populations in paddy soils.The results provide an important basis for boosting soil C accrual in the subtropical rice-growing areas. 展开更多
关键词 bacterial community keystone bacterial taxa mean weight diameter mineral-associated organic carbon particulate organic carbon structural equation modeling
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新时期中国农业技术创新的发展战略 被引量:4
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作者 李哲敏 《科学管理研究》 CSSCI 北大核心 2003年第4期1-4,共4页
技术创新是科技创新的有机组成。本文在分析现阶段中国农业技术创新存在的问题的基础上 ,提出近 10年中国农业技术创新的发展目标。
关键词 中国 农业技术 技术创新 发展战略 科技创新 科技产业化 生态环境 激励机制 知识产权
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社会主义新农村建设的内涵、重点和政策取向 被引量:2
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作者 王万山 庄小琴 《石家庄经济学院学报》 2007年第4期26-29,共4页
阐述了中央关于社会主义新农村建设20字方针的内涵,从"六新",即新农民、新产业、新村庄、新组织、新环境和新服务方面论述社会主义新农村建设的重点,最后提出社会主义新农村建设应主要实施的政策措施,包括确立战略目标及其相... 阐述了中央关于社会主义新农村建设20字方针的内涵,从"六新",即新农民、新产业、新村庄、新组织、新环境和新服务方面论述社会主义新农村建设的重点,最后提出社会主义新农村建设应主要实施的政策措施,包括确立战略目标及其相配套的政策、把政策的着力点放在解决农民的"民生"问题、经济成长和农村环境保护上等。 展开更多
关键词 社会主义新农村 内涵 重点 政策取向
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