oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 110 )

2018 ( 1888 )

2017 ( 1961 )

2016 ( 2045 )

Custom range...

Search Results: 1 - 10 of 86769 matches for " 滕鹏国 "
All listed articles are free for downloading (OA Articles)
Page 1 /86769
Display every page Item
新媒体对大学新生入学适应的影响及教育策略
,金盛华,马莹华
- , 2015, DOI: 10.15936/j.cnki.10083758.2015.03.011
Abstract: 摘要 新媒体的出现深刻改变了人们的沟通方式乃至生活的各个方面。从社会支持的视角对大学新生入学适应的本质进行系统分析,进而结合新媒体这一新兴沟通媒介所带来的个体之间联系方式的变化,尤其是个体在社交网络和信息传递方式上的革命性变革,对新媒体条件下大学新生在人际关系、信息沟通和学业活动中表现出的新特点进行剖析阐释。同时借助新媒体所具有的特点与优势,通过搭建新生入学前的技术平台、优化多元教育措施、整合利用支持资源等方式,提出帮助新生全面适应大学生活的具体措施。
Abstract:The emergence of new media has profoundly changed the ways of peoples communication and affected various aspects of peoples life. From the perspective of social support, this paper systematically analyzes the nature of university freshmens school adaption. Taking into account the changes of contact among individuals brought by new media, especially the revolutionary changes of individuals social networking and information transferring, the new characteristics in interpersonal relationships, information communication and academic activities are analyzed. Meanwhile, turning to the features and merits of new media, this study points out specific measures to help university freshmen adapt to college life by building technological platforms before entrance, optimizing diversified educational measures and integrating the use of support resources, etc.
小学教师科学素养的调查研究
张奇1,1,郑琳娜1,王彦静2
心里发展与教育 , 2003,
Abstract: 为了解大连地区小学教师科学素养的现状,采用自编调查问卷对265名大连市城乡小学教师进行了调查研究。结果表明:1)本、专科学历小学教师的科学素养明显高于中专学历的教师;2)小学教师较好地掌握了小学水平的科学知识,但对中学以上水平的科学知识掌握较差;3)教师的科学素养水平没有表现出随教龄的增长而提高。
梨两个休眠相关mads-box基因特征及在其休眠过程中的表达分析
,,sayed,hussain,元文
园艺学报 , 2013,
Abstract: ppmads1和ppmads2是从‘酥梨’(pyruspyrifoliawhitepeargroup‘suli’)休眠芽转录组文库筛选的两个与休眠相关的mads-box基因序列。为了解序列的特征,对其进行了相关生物信息学分析,并以‘翠冠’和‘圆黄’梨为试材,用实时定量pcr技术分析其花芽休眠不同阶段的表达变化。结果表明:两个基因都具有mads-box家族的特征序列mikc-基序,ppmads1和ppmads2分别与日本梨(p.pyrifolia‘kosui’)休眠相关的两个mads-box基因ppmads13-1和ppmads13-2聚在一起,且单独聚为一支,与李属植物休眠相关的mads-box基因关系最近。在两个品种的休眠过程中,ppmads1和ppmads2的表达呈现相似的变化趋势,都有一个表达高峰,但‘翠冠’梨ppmads1和ppmads2的表达高峰均出现在11月15日,而‘圆黄’梨ppmads1的表达高峰延后到12月30日,ppmads2的表达高峰出现在12月15日。两个品种ppmads1和ppmads2的表达高峰都出现在内休眠解除之前,随内休眠解除其表达量下调,在生态休眠阶段表达量维持在较低的水平。据此推测ppmads1和ppmads2的表达对梨芽内休眠的解除具有调控作用
‘翠冠’梨花芽休眠期碳水化合物变化及其相关基因表达研究
,,sayed,hussain,元文
园艺学报 , 2013,
Abstract: 以‘翠冠’梨(pyruspyrifolianakai)花芽为试材,连续两年研究了其在休眠过程中的碳水化合物含量变化及编码α–淀粉酶、β–淀粉酶和α–葡聚糖磷酸化酶等碳水化合物代谢相关基因的表达模式。两年的结果显示,随着‘翠冠’梨花芽休眠的加深,可溶性糖含量逐渐下降,11月15日降到最低。此后,在内休眠及其解除过程中可溶性糖含量呈上升趋势。花芽中淀粉含量随着休眠的加深逐渐下降,最低含量出现的时间在年度间有所不同。随着休眠开始解除,淀粉含量逐渐增加,在完全解除前达到最大值,其后则逐渐下降。‘翠冠’梨花芽的ppamy、ppbam1、ppbam2和ppphs在内休眠阶段均出现一个表达高峰,然后逐渐下降直到内休眠完全解除前。之后,除ppbam2外,其余3个基因再次上调表达。‘翠冠’梨花芽休眠期间,淀粉含量的变化与ppamy、ppbam1、ppbam2和ppphs的表达变化之间存在联系,由此推测这些基因可能参与了‘翠冠’梨花芽休眠期碳水化合物代谢的调控。
‘小香水’梨果实后熟过程中挥发性组分分析
,贾惠娟,王强,张茂君,元文
园艺学报 , 2012,
Abstract: 采用顶空固相微萃取结合气相色谱质谱联用技术分析了秋子梨‘小香水’(pyrusussuriensismaxim.‘xiaoxiangshui’)果实后熟过程中果实挥发性组分的变化。结果表明,‘小香水’梨果实在20℃后熟过程中挥发性组分的种类及含量均表现为增多的趋势。共检测到酯类、醛类、醇类、酸类及萜类5大类共计38种挥发性物质,其中15种为整个后熟过程中的共有组分。5大类挥发性组分中酯类物质的种类最多,其含量在后熟过程中增幅最大,后熟9d时达到最高。‘小香水’梨在后熟过程中共检测出包括醛类和酯类在内的10种特征香气组分,其中2–甲基丁酸乙酯、己酸乙酯及丁酸乙酯在9d时香气值分别为668.09、279.58、190.60。20℃后熟6~9d为食用最佳时期。
79-1型伏安分析仪及其性能测试
陆宗,庄群猛,可新,谢光,张东华
环境科学 , 1982,
Abstract: 伏安分析法具有灵敏、准确、多用途和廉价等优点,是一种重要的痕量分析方法.采用集成电路(微处理机)的极谱仪使测量和读出闭环,仪器的精度和自动化程度显著提高.目前国内已有集成电路快扫描极谱仪和脉冲极谱仪市售。
儿童的几何图形预期表象
张奇,,李庆安,林洪新,张黎,朱会明
心理学报 , 2006,
Abstract: ?将儿童几何图形预期表象分为两种水平,即再认水平的预期表象和生成水平的预期表象。采用“平移”、“对称”、“重叠”三种平面几何图形的预期表象作业和“展开”、“旋转”、“截面”三种立体几何图形的预期表象作业考察了3至12岁儿童几何图形预期表象的发生和发展。结果表明:儿童再认预期表象的发生早于生成预期表象的发生;儿童预期表象的发生和发展明显受几何图形类型和作业类型的制约
浑河冲洪积扇土壤硝酸盐污染特征及相关因素分析
左锐,,,王金生,孙岳
南水北调与水利科技 , 2013,
Abstract: 土壤硝酸盐是地下水硝酸盐的重要来源,因此土壤硝酸盐特征研究对于土壤和地下水污染控制与修复具有重要意义。为了探讨沈阳浑河冲洪积扇封硝酸盐污染特征,在浑河洪积扇横跨浑河设计了5个监测断面、50个取样点,每个取样点按0.8m进行了垂向深度取样和硝酸盐测定。随后,利用hazen概率曲线确定了浑河冲洪积扇土壤硝酸盐含量的标准值,采用单因子指数法和内梅罗污染指数评价法,对不同断面和不同深度土壤硝酸盐的污染特征进行了分析,并将区域污染特征与区域土地利用类型、区域有机质含量进行关联分析,判定其对硝酸盐污染的影响。研究结果显示,本区硝酸盐浓度标准值约为2.58mg/kg;区域硝酸盐中度污染;排污河的存在、区域土地利用类型和区域有机质含量对区域硝酸盐污染关系密切,在分析硝酸盐污染过程中应予以重点考虑。
随机阵列码:一种高容灾易扩展的RAID存储容灾方法
,张景中,陈亮,王晓京
- , 2017, DOI: 10.15961/j.jsuese.201600492
Abstract: 中文摘要: 针对RAID存储容灾系统中数据存储的可靠性和扩展性等问题,提出一种具有较高容灾能力且易扩展的存储容灾方法,称之为随机阵列码。通过研究 GF(2)上随机矩阵列满秩的性质,并将其应用在RAID存储容灾方案中。首先,依据RAID存储系统的环境配置和容灾需求设置条带参数;其次,构建相应规模且满足特定性质的随机矩阵作为编码矩阵;最后,将原始数据等分成块,利用编码矩阵将其编码并折叠存储到不同磁盘上。当发生磁盘损毁、扇区失效等原因造成数据丢失时,可依据相应的校验矩阵及剩余的编码分块进行失效数据的高概率译码恢复,从而,实现了数据高效、可靠地容灾存储。实验验证及理论分析表明:1) GF(2)上的随机高矩阵,在随机概率 p=0.5,矩阵行列差 δ ≥15时,即具有高概率列满秩的性质;2)随机阵列码的编码参数,不再受到素数或有限域规模的限制,可灵活设置,其容灾能力也可根据容灾需求进行扩展,并可实现较多的容错模式;3)随机阵列码由于基于XOR运算,在均匀随机时与RS码、CRS码相比,具有较高的编译码速率,特别是在较大规模的编码构造中表现良好;4)随机阵列码随着规模的增长,可趋于近似MDS码,具有较高的存储空间利用率。基于随机阵列码高效,可靠,易扩展等特点,可实现一般化RAID存储容灾方案的构造,此外,也可与其他存储容灾技术结合使用,共同构建特定需求下的RAID存储容灾系统。
Abstract:To improve the reliability and scalability of data storage in redundant arrays of inexpensive disks (RAID) storage system,a new kind of storage fault-tolerance method with high fault-tolerance and flexible scalability was proposed,named random RAID.A research on the properties of random matrices in GF(2) was conducted and applied in the RAID storage fault-tolerance system.At first,the stripe parameters were set by the storage environment configuration and fault-tolerance requirement,then a random matrix was created as the generator matrix,with corresponding scale and some specific properties.Finally,the origin data was split into blocks with equal size, and encoded by the generator matrix, then folded into different disks.When there were data loss caused by disk damage or sector failures,the lost data could be recovered by the corresponding parity-check matrix and the remaining encoded blocks with high probability,enabling efficient and reliable data storage.Theoretical and experimental results show that:1) When random probability p=0.5 and the subtraction of row and column δ ≥15,the random high matrix in GF(2) could be full column rank with high probability;2)The encoding parameters of random RAID weren't constrained by the prime or scale of finite field any more.Instead,they can be set flexibly.The fault-tolerance can also be scaled with different fault-tolerance requirements, and allow more error patterns;3)When using uniform random matrix and compared with RS and CRS,the random RAID can improve the speeds of encoding and decoding greatly thanks to XOR operations,especially in large scale coding constructions;4)With the growth of the scale,the random RAID tends to approximate MDS,thus realizing highly efficient storage.Due to the properties of efficiency,reliability and scalability,the random RAID can realize the general construction of RAID storage fault-tolerance system.Moreover,it can be combined with other fault-tolerance technologies to construct
逆码:一种可容3错的低密度MDS横式阵列码方法
陈亮,袁德砦,,王晓京
- , 2017, DOI: 10.15961/j.jsuese.201700066
Abstract: 中文摘要: 磁盘阵列存储可采用阵列码技术提高系统的容错能力。随着对阵列存储系统的深入认识,阵列码的更新效率也逐步成为一项重要的性能指标。针对当前可容3错横式阵列码更新效率低的问题,提出了一种具有低密度特性的横式阵列码构造方法,称为逆码。不同于传统阵列码是利用特殊几何方法确定编码过程,逆码是从生成矩阵角度出发,通过构造编码分布矩阵确定编码过程。首先,基于域 GF(2 w)给出了一种具有超正规性质但只有3行元素的矩阵结构,称为逆结构矩阵;然后,利用 w× w大小的比特方阵表示域 GF(2 w)中元素;最后,通过提出的优化算法得到具有低密度性质的编码分布矩阵,进而确定逆码的编码过程。理论分析表明:逆码满足最大距离可分性质,可取得最优的存储效率;与STAR码、RTP码等容3错的阵列码相比,逆码的参数取值范围将不受素数的限制,参数设置更加连续。实验分析表明:相比于同样从生成矩阵确定编码过程的CRS码,逆码的稀疏度、更新效率以及编译码效率均有明显优势;相比于STAR码、RTP码,逆码的更新效率平均可提高20 %;为了提高逆码的译码效率,文中也尝试了不同的异或序列技术。
Abstract:Array codes are widely used to improve the fault tolerance ability of redundant arrays inindependent disks(RAID) storage system.With the in-depth understanding of RAID storage system,the update efficiency of array codes has gradually become an important performance metric.In order to deal with the low update efficiency problem of current triple fault tolerant horizontal array codes,a new kind of low-density and triple fault tolerant horizontal array code called inverse code was proposed.Unlike the traditional array codes whose encoding process was determined by using special geometric methods,the encoding process of inverse codes were determined by constructing coding distribution matrix in generator matrix.Firstly,a matrix structure based on GF(2 w) called inverse structure matrix was proposed,which is a super-regular matrix and contains only three rows of elements.Secondly,bit square matrices of size w× w were used to represent the elements of GF(2 w).Finally,the coding distribution matrix with low density property was produced by a new optimized algorithm and used to determine the encoding process of inverse code.Theoretical analysis showed that the inverse code was maximum distance separable and obtained the optimal storage efficiency.Moreover,the parameters of inverse code were not constrained to be prime numbers and more continuous compared with other triple fault tolerant horizontal codes such as STAR code and RDP code.Experimental results showed that inverse code had the advantages in sparse degree,update efficiency,encoding and decoding efficiency over CRS code whose encoding process was determined by constructing generator matrix.Compared with STAR code and RDP code,the update efficiency of inverse code was improved by 20 % on average.Besides,different kinds of ‘XOR scheduling’ techniques were used to improve the decoding efficiency of inverse code.
Page 1 /86769
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.