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Search Results: 1 - 10 of 5682 matches for " 刘欢雨 "
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贵州基础设施资本存量与经济增长的关系研究
The Research of Guizhou Infrastructure Capital and Economic Growth
 [PDF]

刘欢
Service Science and Management (SSEM) , 2012, DOI: 10.12677/SSEM.2012.12005
Abstract:

  要:基础设施是国民经济赖以发展的基础。本文通过永续盘存法估计了贵州1993年到2010年的基础设施资本存量,并将估计出的基础设施资本存量与贵州经济增长指标进行相关分析。从而证明基础设施的增加或改善对贵州的经济发展有积极地促进作用。

Abstract: The infrastructure is the foundation of the national economy development. This article estimates the infrastructure capital stock of Guizhou in 1993 to 2010 through the perpetual inventory method, and will estimate the related analysis between the infrastructure of the capital stock and Guizhou economic growth indexes. It is proved that increasing or improving infrastructure has actively promoted role on the economic development in Guizhou.

 

基于SVAR模型研究实际利率对我国A股市场的影响
Based on SVAR Model to Research the Actual Interest Rate in the Influence of the A Share Market
 [PDF]

刘欢
Advances in Applied Mathematics (AAM) , 2012, DOI: 10.12677/AAM.2012.11005
Abstract: 股票市场的变化受很多个因素影响,其中市场利率的变动和也是影响股票市场变化的因素。本文选取SVAR模型对中国A股市场2001~2011年的股票价格与成交量及实际利率变动之间的关系进行实证分析。研究表明:实际利率变化对我国股市波动性存在影响,但这种影响很微弱;实际利率变化与股市波动性的关系为负。
There are many factors affect the change of the stock market, and market interest rate movements is also one of the stock market change factors. This paper selects SVAR model to the A share market 2001-2011 years of stock price and volume, and the actual interest rate changes the relationship between the empirical analysis. Research shows that: The actual interest rate changes of Chinese stock market volatility influence existence, but the effect is very weak; The actual interest rate changes and stock market volatility of negative relationship.
金纹细蛾及其寄生蜂种群动态的模糊聚类分析
刘欢
河南农业科学 , 2015,
Abstract: 金纹细蛾(LithocolletisringoniellaMatsumura)是我国苹果产区的重要潜叶害虫,为了利用寄生蜂开展苹果园金纹细蛾的生物防治,调查了金纹细蛾及其寄生蜂发生的种群动态,并对两者种群动态进行了模糊聚类分析。结果表明:金纹细蛾对苹果的危害时间较长,始发生于6月初,并持续危害到10月底;7月中旬至9月中旬是金纹细蛾发生高峰期,存在明显的世代重叠现象。寄生蜂始发期晚于金纹细蛾,7月和8月是寄生蜂的发生高峰期。10月后金纹细蛾幼虫和寄生蜂的发生量均逐渐下降。金纹细蛾种群的22次调查结果可以聚为6类,λ=0.968;其寄生蜂的调查结果聚为4类,λ=0.982。聚类结果表明了苹果园中金纹细蛾及其寄生蜂种群动态随季节变化的差异,同时反映了金纹细蛾的种群消长与其寄生蜂的数量密切相关,寄生蜂是抑制苹果园金纹细蛾种群增长的主要因素之一。
鲫鱼新鲜度近红外定量预测模型的建立
刘欢
- , 2015, DOI: 10.13982/j.mfst.1673-9078.2015.7.028
Abstract: 为实现鲫鱼新鲜度的快速测定,本文基于近红外漫反射光谱定量分析技术和化学计量学方法,采集了144个鲫鱼鱼肉样品在1000~1799 nm范围内的光谱数据,测定了鲫鱼样品的pH、TVB-N含量、TBA含量和K值四种新鲜度指标;在确定近红外光谱数据最佳预处理方法和适宜波段的基础上,分别采用偏最小二乘法、主成分分析和BP 人工神经网络技术、偏最小二乘法和BP 人工神经网络技术建立了鲫鱼新鲜度定量预测模型。结果表明,鲫鱼样品四种指标数据范围均较大,可满足建模要求。以pH为鲜度指标时,采用偏最小二乘法和BP 人工神经网络技术建立的模型最好,其定标相关系数为0.9945;以TVB-N、TBA和K值为鲜度指标时,采用偏最小二乘法建立的模型最好,其定标相关系数分别为0.9857、0.9985和0.9952。建立的四种鲜度指标定量模型均具有较好的预测能力。
To rapidly determine the freshness of crucian carp (Carassius auratus), near-infrared (NIR) diffuse reflectance spectroscopy- based quantitative analysis coupled with chemometric methods was used to collect spectral data in the range of 1000~1799 nm for 144 carp samples. Freshness quality indexes including pH, total volatile basic nitrogen (TVB-N) content, the thiobarbituric acid (TBA) value, and the K value were measured for all samples. After the optimum spectral pretreatment method and suitable spectra bands were determined, quantitative prediction models for crucian carp freshness were established using partial least squares (PLS) regression, principal component analysis (PCA) combined with back propagation artificial neural network (BP-ANN), and PLS combined with BP-ANN. The ranges of the four indicator values for crucian carp samples were wide and met the assumptionss for modeling. When pH was used as the freshness indicator, the prediction model developed using PLS combined with BP-ANN was the best, and the correlation coefficient was 0.9945. When the TVB-N content, TBA value, and K value were used as freshness indicators, PLS prediction models were the best, and the corresponding correlation coefficients were 0.9857, 0.9985, and 0.9952, respectively. The established quantitative models for the four freshness indicators all had strong prediction capabilities.
农村贫困的父辈代际传递与子辈户口迁移削弱效应研究
刘欢
中央财经大学学报 , 2017,
Abstract: 摘要 笔者基于中国综合社会调查(CGSS)数据库数据,运用OLS回归模型实证检验了在不同样本下随户口迁移变化的父辈贫困代际传递效应的显著性影响,结果显示:在不同样本下,父辈收入对子辈收入都有明显的正向传递效应;引入子辈迁移变量及交互项后,迁移交互项明显削弱了父辈收入的传递效应,其中低收入、绝对贫困家庭样本的削弱程度明显要高于全样本的削弱效应。在进一步的分析中,对于未接受过高等教育的子辈,迁移能够明显提高其收入,且其对代际贫困的削弱效应要高于接受过高等教育的;而在非高收入家庭的迁移类型中,省外迁移明显增加了子辈收入,外省迁移与父辈收入交互项对代际传递效应的削弱作用更加明显。对代际贫困传递因素分解后回归结果显示,迁移强化了BMI值、教育以及社会网络对子辈收入的正向效应。最后,根据实证结论提出应完善各项保障措施,减少个人迁移的成本等政策建议。
功能基因组学在非综合征型唇腭裂遗传结果功能研究中的应用
Implementation of Functional Genome in the Functional Study of Non-coding Variants Associated with Non-syndromic Cleft Lip with or without Cleft Palate.

刘欢
- , 2018, DOI: 10.13701/j.cnki.kqyxyj.2018.12.001
Abstract: 摘要 唇腭裂是口腔常见的先天性颅颌面缺损,部分患儿的发病与遗传背景有关。全基因组关联分析(genome-wide association study,GWAS)等研究揭示了多个与该疾病相关的易感基因位点在基因组非编码DNA区域,由于我们对于这些非编码DNA在人唇腭发育过程中的功能缺乏了解,因此对有效的易感基因位点进行系统化生物学验证成为唇腭裂遗传学结果向临床转化中的难点。本文通过对人及小鼠颅颌面发育组织特异性功能基因组结果及机器学习可能的应用方式进行系统阐述,初步建立唇腭裂相关非编码DNA突变功能研究的完整体系
不同施氮方式对甘蔗氮肥效率及氮素去向的影响
韦剑锋,韦冬萍,陈超君,蓝立斌,刘欢,梁和
核农学报 , 2013,
Abstract: 以新台糖22号(ROC22)为试材,通过网室盆栽试验方法,在总施氮量(15N标记尿素5g/盆,相当于450kg·hm-2)相同条件下,研究了全部基施(T1)、50%基施+50%在分蘖期追施(T2)和30%基肥+30%在分蘖期追施+40%在伸长期追施(T3)3种施氮方式对甘蔗氮肥效率与氮素去向的影响。结果表明甘蔗吸收的氮素约18%~29%来源于当季施用的尿素氮,71%~82%来自土壤和种茎氮;氮肥利用率为21.0%~34.52%,残留率为37.61%~44.13%,有21.35%~41.39%的氮素损失。3种施氮方式下,氮肥残留在0~20cm土层较多,在20~40cm残留较少。随氮肥施用时间后移,甘蔗吸收的氮素、来源于肥料氮素的比率、氮肥利用率、氮肥残留率、蔗茎产量及产糖量明显增加,而氮肥损失率显著下降,蔗茎的氮素分配率和蔗糖分积累略呈下降趋势,同时氮素在0~20cm土层的残留呈上升趋势,在20~40cm土层呈下降趋势。从经济效益和环境效益考虑,T3施氮方式的效果较为理想。
叶面追肥对马铃薯干物质积累、营养状况及土壤养分的影响
韦冬萍,韦剑锋,吴炫柯,刘欢,熊建文,史丹妮
河南农业科学 , 2013,
Abstract: 在施肥总量相同基础上,以马铃薯品种合作88号为试材,于现蕾后分别叶面喷施0.5%尿素、0.3%KH2PO4及其混合溶液各3次,每次喷液量为1500kg/hm2,研究叶面追肥对马铃薯干物质积累、营养状况及土壤养分的影响。结果表明:不同叶面追肥对马铃薯及土壤的影响有较大差异。其中喷施0.5%尿素或0.5%尿素+0.3%KH2PO4处理能明显提高马铃薯干物质积累量、生物产量、鲜薯经济产量及叶片氮含量,但明显降低了土壤有机质、氮及磷含量;喷施0.3%KH2PO4处理对马铃薯叶片和土壤钾含量提高作用最为明显,但显著降低块茎氮、磷及钾含量。可见,在设置试验条件下,叶面追施氮肥的增产效果较好。
复合肥施用量对麻疯树幼苗生长及养分吸收的影响
韦冬萍,韦剑锋,吴炫柯,刘欢,胡江如
河南农业科学 , 2015,
Abstract: 以麻疯树FD-8号为试材,采用盆栽方式,研究复合肥施用量(0~30g/盆,折算后为0~4.246t/hm2)对秋播麻疯树种子萌发、幼苗生长及养分吸收利用的影响。结果表明:施用复合肥能明显加快麻疯树幼苗出土,促进幼苗生长,提高植株N、P、K含量和积累量。但随着施肥量的增加,麻疯树出苗率、根系生长量、地径、茎高、干物质积累量、苗木质量指数及植株N、P、K积累量先增加而后下降,肥料N、P、K养分利用率则显著下降。其中,复合肥(N∶P2O5∶K2O=28∶6∶6)施用量10g/盆(折算后为1.415t/hm2)的综合效应最好。
批判性思维研究热点知识图谱
The Mapping Knowledge Domains Based on the Hotspots Research of Critical Thinking in China
 [PDF]

刘欢, 胡瑜
Advances in Psychology (AP) , 2014, DOI: 10.12677/AP.2014.46111
Abstract:
为了了解国内近几年批判性思维研究的重点和热点,本研究采用Bicomb软件和SPSS软件对从中国知网中标准化查询的2010~2014年的314篇文献分析绘制了批判性思维研究的知识图谱。结果表明,我国批判性思维研究热点主要围绕两大主线和三个领域展开。两大主线为:批判性思维培养和教学的研究,方法和内容的研究;三大领域包括:批判性思维的核心构成和培养;批判性思维的教育教学策略以及批判性思维的教学内容和教育改革。
In order to understand the domestic research hotspots on critical thinking in recent years, this study used the software of Bicomb and SPSS analyzing 314 papers from 2010 to 2014 which were selected from CNKI to draw critical thinking knowledge map. The results showed that our critical thinking research focused mainly on two main lines and three areas. Two main lines were: research on training and teaching of critical thinking as well as methods and contents; three areas include: core structure and culture of critical thinking, teaching strategies of critical thinking, and education content and reform of critical thinking.
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