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Search Results: 1 - 10 of 120052 matches for " 任晓晨 "
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碧利斯(0604)暴雨增幅的云微物理成因
,
中国科学 地球科学 中国科学 地球科学 , 2014,
Abstract: ?2006年“碧利斯”台风登陆中国大陆后,在湖南、广东和江西三省交界附近地区造成明显暴雨增幅,造成十分严重的灾害,影响巨大.本文利用高分辨率数值模拟资料,从微观云物理过程角度出发,研究了“碧利斯”暴雨增幅发生前和增幅强降水发生时段云微物理特征的差异,探讨了登陆台风暴雨增幅云微物理方面的可能成因,结果指出:暴雨增幅前后,强降水区云微物理特征存在明显不同,与降水强度的明显增强相伴,云中各种水凝物含量也明显增加,其中云冰、雪和霰等固态水凝物的增加尤为显著,冰相过程对地面降水的贡献明显加大,降水云系发展旺盛、高大;云微物理转化率的对比分析发现,暴雨增幅时段,由水汽凝结过程显著增强所带来的云水的增加,主要通过两个途径作用于暴雨增幅:一是通过云中雨水对云水的碰并收集,促进雨水含量显著增加,进而增强地面降水;二是通过云中雪粒子对云水的碰并造成雪粒子含量增加,增加的雪粒子又被云中霰粒子碰并收集造成霰含量增长,进而由霰粒子融化为雨水,并最终作用于地面降水的增幅.文中最后通过分析总结给出了“碧利斯”暴雨增幅云微物理成因示意图.
虚拟分子印迹与表面增强拉曼散射联用技术用于孔雀石绿的超灵敏检测
马芳,李欣,
- , 2017,
Abstract: 摘要 采用抗坏血酸还原法制备Ag球粒子,然后用3-(甲基丙烯酰氧)丙基三甲氧基硅烷使其表面硅烷化,最后用虚拟模板分子松香酸代替模板分子孔雀石绿与功能单体甲基丙烯酰胺反应合成虚拟印迹聚合物.结果表明,生成的"核-壳"式复合基底比Ag的表面增强拉曼散射(SERS)增强效果显著,其对孔雀石绿的最低检测浓度达到10-11 mol/L.该方法实现了背景噪音的消除,提高了分析结果的准确性,为有机染料的超灵敏检测提供了参考
面向软件仓库挖掘的数据驱动特征提取方法
,江贺?,志磊?
计算机科学 , 2015, DOI: 10.11896/j.issn.1002-137X.2015.09.031
Abstract: 在软件仓库挖掘领域,通常将软件工程任务转换成数据挖掘问题进行解决。领域特征的使用严重影响了软件任务的解决效果。然而,如何根据特定任务从软件仓库数据中提取有价值的特征,在软件仓库挖掘领域尚缺乏系统的研究。数据驱动特征提取方法是一种新的特征提取方法。对于给定的软件工程任务,该方法从任务的数据集中选取部分数据(如源代码、缺陷报告等),招募若干志愿者人工完成该任务,并要求志愿者说明在人工完成特定软件工程任务时所考虑的因素。通过分析这些因素,可以提取所需的领域特征。以缺陷报告摘要任务为例进行实验,结果表明新方法能够发现高效的领域特征,并取得比现有方法更好的预测效果。
Research of distributed data stream query reusing algorithm
一种分布式数据流查询重用算法研究*

ZHANG Fu zhi,REN Xiao chen,
张付志
,

计算机应用研究 , 2008,
Abstract: This paper proposed an algorithm of distributed data stream query reusing. Firstly, query trees existing in distributed DSMS matched with the new query tree created by the distributed DSMS and calculated reusing proceeds. Secondly, reused the overlapped query operators between the existing query trees and the new query tree based on the reusing proceeds.
有限区域流函数和速度势的3种求解方法在分析台风bilis暴雨增幅中的比较研究
,曹洁,王黎娟,
气候与环境研究 , 2013, DOI: 10.3878/j.issn.1006-9585.2012.12145
Abstract: 将有限区域流函数、速度势求解中常用的两种张驰法(即理查逊法和加速利布曼法)与调和—余弦谱展开法(h-c法)进行了比较,理论研究表明:h-c法单独考虑边界影响分量,物理意义明确,且不会丢失边界上的天气系统;从计算上看,h-c法重建的风场能精确还原原始风场,且计算效率明显高于两种张驰法,即收敛更快。通过在台风bilis(0604)暴雨增幅过程诊断中的应用发现,常用的两种张驰迭代方法在求解有限区域流函数和速度势的问题上效果都不是很好,即:用理查逊法和加速利布曼法计算的流函数和速度势重建的风场与原始风场差别较大,不能准确还原原始风场;用h-c法不仅计算效率高,还原的风场与原始风场差异极小,且不受南边界较强的西南季风涌影响,在暴雨增幅前期能较好地反映与暴雨增幅相关的强辐合信号。因此,可用h-c法计算得到的无辐散风和无旋风对有限区域的天气系统进行更深入的动力结构分析。
热轧带钢氧化铁皮拉伸开裂行为 Tensile cracking behavior of oxide scale in hot-rolled steel
王尚,杨荃,云鹤,,单忠德
- , 2017,
Abstract: 采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和万能拉力试验机,研究了Q235-A带钢氧化铁皮的组织、结构及其开裂行为.结果表明,氧化铁皮的成分主要为Fe3O4、Fe2O3和Fe,含有少量的Fe O,氧化层厚度比较均匀,约为10μm,结构致密且与基体结合较好.拉伸实验表明,随着应变的增加,裂纹条数增加呈先慢,后快,再慢的规律.应变达到0.05%时氧化铁皮开始出现裂纹,当应变在0.08%~0.10%范围内裂纹条数随应变增加非常明显,当应变超过0.10%时裂纹条数增加缓慢,应变超过0.15%时裂纹条数几乎不再增加.
基于信道占用率的Ad Hoc网络自适应公平性算法
Channel occupancy rate-based adaptive fairness algorithm for Ad Hoc network

,刘全利,志磊,赵莹
- , 2016, DOI: 10.7511/dllgxb201601007
Abstract: Ad Hoc网络中,节点通过竞争信道完成通信,如果竞争窗口值选取策略不合理,则容易造成公平性问题.在分析现存典型公平性算法的实现机制基础上,提出了信道占用率的概念,设计了一种基于信道占用率的Ad Hoc网络自适应公平性算法.根据节点对通信历史及当前信道占用率与理想信道占用率之间的关系,将通信情况分为4种类别,再结合当前网络负载情况,动态设置竞争窗口值.仿真结果表明,该算法在改善吞吐量的同时,显著提高了节点信道接入公平性,在各种负载条件下表现良好,优于BEB、MILD、MIMD和NAVB等算法.
In Ad Hoc network, nodes compete channels to communicate. It is likely to cause fairness problems if the selection strategy of collision window value is unreasonable. With the analyses of the implementation mechanisms of existing typical fairness algorithms, a concept of channel occupancy rate is raised. Based on this concept, an adaptive fairness algorithm for Ad Hoc network is proposed. The network correspondence is classified into four types according to the history of correspondence and the relationship between the current channel occupancy rate and the ideal channel occupancy rate. In each type, the collision window value of node is set dynamically based on the current network load. Simulation results show that the proposed algorithm performs well under various load conditions. It can significantly improve fairness of channel access among nodes as well as throughput, so it is better than BEB, MILD, MIMD and NAVB algorithms.
髓样细胞触发受体-1在寻常型银屑病中的表达及意义
Expression of Trem-1 and its significance in psoriasis vulgaris

,,,,,,建文,,肖生祥
- , 2016, DOI: 10.7652/jdyxb201603026
Abstract: 摘要:目的 通过对比髓样细胞触发受体-1(Trem-1)在寻常型银屑病患者与正常人皮肤组织及血液中的表达差异,探索寻常型银屑病发病的可能机制。方法 采用免疫组化及实时荧光定量PCR的方法检测Trem-1在不同组织中的表达情况,应用SPSS21.0统计软件进行统计学分析。结果 Trem-1在寻常型银屑病患者皮损中表达增加,主要表达于表皮全层,正常皮肤组织中主要表达于基底细胞层,其表达差异具有统计学意义(P<0.05)。Trem-1 mRNA在寻常型银屑病皮损、血液中表达升高,与正常组相比差异具有统计学意义(P<0.05);且Trem-1mRNA表达与银屑病皮损面积和严重程度指数(PASI)呈正相关(P<0.05)。结论 Trem-1的异常表达可能参与了寻常型银屑病发病,Trem-1可能成为治疗寻常型银屑病的潜在靶点。
ABSTRACT: Objective To study the expression of triggering receptor expressed on myeloid cells-1 (Trem-1) in psoriatic vulgaris and normal skin tissues and blood, and to explore the potential pathogenesis of psoriasis. Methods Immunohistochemistry and Real-time PCR were used to detect the expression of Trem-1 in the blood and tissues of normal skin and psoriasis. Results The positive expression rate of Trem-1 in psoriatic lesion was significantly higher than normal tissue. Trem-1 was expressed in the whole epidermis, with a significant difference (P<0.05). The mRNA expression of Trem-1 was significantly higher in psoriatic skin tissues and blood than in normal skin tissues and blood (P<0.05). Moreover, the mRNA expression of Trem-1 was positively correlated with PASI (P<0.05). Conclusion Abnormal expression of Trem-1 might be related to the pathogenesis of psoriasis. Trem-1 will cure psoriasis vulgaris as the potential therapeutic target
基于粗糙集机器学习的全生命周期造价估算方法研究
Based on Rough Set Machine Learning of WLC Estimation Method
 [PDF]

景晨光,
Software Engineering and Applications (SEA) , 2013, DOI: 10.12677/SEA.2013.22009
Abstract:

本文利用粗糙集理论在知识发现上的优越性,结合机器学习的原理,以实际工程量清单样本为例,研究了历史数据不确定性影响下全生命周期造价的估算问题。在结合具体实例的基础上,给出了粗糙集从建模、有效数据筛选到决策规则生成、最终得出全生命周期造价结果的完整估算过程。本文尝试在全生命周期造价估算中引人粗糙集机器学习理论,从大量实测工程数据中优选出最有影响的因素,在保持决策属性和条件属性之间的依赖关系不变化的前提下,根据其等价关系寻找工程知识库中的冗余关系,从而简化决策表,确保其分类能力,约简掉联系较弱的因素,最后以粗糙集决策规则学习的形式实现造价预测。通过混淆矩阵交叉验证表明,应用粗糙集理论解决数据不确定性影响下的全生命周期造价估算是可行的。
In this paper, rough set theory in knowledge discovery on the superiority of the combination of machine learning theory to the actual sample quantities, for example, the uncertainty of the historical data under the influence of life cycle cost estimation problem. In the light of the specific examples based on rough sets is given from the modeling, the effective data screening to decision rules generation, life cycle cost of the final results obtained the complete estimation process. This paper attempts to estimate life cycle cost of the introduction of rough set theory of machine learning, data from a large number of experimental works of the most influential factors in selection, the decision attribute and condition of maintaining the dependencies between attributes does not change the premise, according to engineering knowledge base to find the equivalence relations between the redundancy to simplify the decision table, to ensure that their classification ability, reduction factor out the weak links, and finally to study rough set decision rules are implemented cost forecast. Confusion matrix by cross-validation showed that the application of rough set theory under the influence of data uncertainty to resolve the full life cycle cost estimate is feasible.

丛枝菌根菌丝桥介导的番茄植株根系间抗病信号的传递
谢丽君,宋圆圆**,,王瑞龙,,叶茂,胡林,张晖
应用生态学报 , 2012,
Abstract: 菌根菌丝桥是植物间在地下进行物质交流的通道,但它能否作为植物间地下化学通讯的通道来传递抗病信号则缺乏研究.本文利用丛枝菌根真菌(amf)摩西球囊霉在供体与受体番茄植株间建立菌丝桥,对供体植株接种早疫病病原菌茄链格孢菌,研究供体与受体番茄植株根系间是否存在抗病信号的传递.荧光定量pcr检测表明,amf侵染后的供体番茄植株再接种病原菌,其根系中苯丙氨酸解氨酶基因(pal)、脂氧合酶基因(lox)和几丁质酶基因(pr3)的转录水平显著高于仅接种病原菌、未接种病原菌和amf,以及只接种amf的番茄植株.更重要的是,与供体有菌丝桥连接的受体番茄根系中pal、lox和pr3的基因的表达量也显著高于无菌丝桥连接、菌丝桥连接被阻断以及有菌丝桥连接但供体植物未接种病原菌的处理,3个基因最高转录水平达到无菌丝桥连接对照受体植物的4.2、4.5和3.5倍.此外,供体植株根系启动防御反应的时间(18和65h)比受体(100和140h)早.表明病原菌诱导番茄供体根系产生的抗病信号可以通过菌丝桥传递到受体根系.
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